(JULY - 2010)

Boy Scouts, Girl Scouts, Kids, Prospecting And Such

     Early Saturday morning, June 26th, a small platoon of PCSC volunteers surfaced at Camp Williams on the East Fork of the San Gabriel River. There we found a mostly sleeping tent city of around 250 Boy Scouts, Girl Scouts, Cub Scouts, and Brownies plus a few dozen adult chaperones. Steve, the Scout Leader, pointed us to places where we best might set up our equipment and then left to oversee the coming day's events. Soon we set up some wing diverters to channel water through our sluices. Joe Chmiel located a good spot for his recently invented highbanker [which sports a clever sorting, sampling basket and inspection platform]. Others arranged tubs and buckets on a picnic table. Then came the rush of young gold seekers.

     Carole Wray had the presence of mind to video what must have resembled a scene out of our 49er ancestors. Later this video was edited and put up on "YOU TUBE". Like they say, a picture is worth a 1000 words and a video is worth a 1000 pictures. For those members who have signed up to receive this Treasure News via e-mail, there is a link that will take you directly to the action!!

     Teaching kids how to pan and operate a sluice provides useful insights into some good and some bad habits. The good: kids have great imaginations that have not yet been overly indoctrinated or jaded, thus they come up with clever ways to cope with, and adapt to, the learning curve. Given timely guidance they become quite proficient. The older ones have remarkably good motor skills and great eyesight. The bad: kids do not have much patience. Some of them can not seem to resist the temptations of sticking fingers into the sluice riffles or into the pans. Some tend to lose focus and begin experimenting with floating downstream in the current or splashing the girls. One thing all had in common: a widening of eyes and the lighting of a mental light bulb after learning how to calculate the value of the gold they recovered. Yikes, $1250 per ounce!! One 12 year old girl in particular decided on the spot that she was going to fill her entire vial up that very day [she already had found a quarter to a half gram that covered the entire bottom of her vial].

     At the end of the day some of us remained for the campfire barbecue. More than one parent inquired about our club. Given the number of kids we have [two of them attended the above event as guests], perhaps some interested parents might consider organizing some junior prospector events??? If so, please drop me a line.

Martin Milas, PCSC President

(JUNE-2010)

Tips On Dealing With Poison Oak

     This is the time of year that often is too hot for prospecting in the desert. The rivers beckon. The birds sing. The gold is pretty. Life is good. But this also is poison oak's back yard. It not only WILL ruin your whole day, but will continue doing so for about three weeks beyond. What to do? Understanding your enemy is the first step.

     Poison ivy, poison oak and poison sumac are a group of closely related plants that secrete an oil known as URUSHIOL [pronounced "you ROO she-awl]. A single nanogram [a billionth of a gram] is sufficient to cause a rash in a sensitive person. 100 nanograms is average for most folks. Even people who seem to be immune can suddenly react. The oil can stay active typically between 1 and 5 years on dead plants and things they touch. At least 50% of all Americans are allergic to it. The key to preventing an outbreak is not to allow the oil to remain on your skin for very long. It takes between 15 minutes and 8 hours for the urushiol active ingredient to chemically bond with skin proteins. Once this happens it can not easily be washed off. Common sources of contamination are prospecting tools such as search coils, picks, boots, gloves and shovels. Dogs also can bring it into your vehicle or home as can clothing or any rucksacks or other baggage items that rub against the leaves, vines or roots. There are several defense strategies and products that work.

     Urushiol oil is relatively easy to rinse off as long as sufficient water is employed. Cold water is said to be best as it does not open up your pores. Soap helps if used early enough, but a specialized product called Tecnu is said to have an ingredient which actually can break the urushiol skin protein bond up to 8 or 12 hours after exposure. I used it on our dog Lilah 2 hours after she crashed through a poison oak thicket just dripping with sap [in a tub using shampoo, apron, and elbow length gloves] with perfect results. I have showered with Tecnu and shampoo with good results. Jill douses our field clothing with it prior to washing. Washing the most common contaminator [your hands] several times a day works well.

     Once a strong reaction sets in, it is too late for Tecnu. There is another product called Zanfel which, for many people, has proved to be a life saver -- even after the boils erupt. It is expensive, though, at nearly $50 per jar. Jill and I have a special, sealable dedicated bag that contains pruning shears, tongs, gloves and Tecnu. We have gotten some good gold from spots into which others dared not venture by taking sufficient time first to clear off the enemy vines and rinsing frequently.

Martin H. Milas, PCSC President

(MAY - 2010)

     The places we prospectors venture for gold also serve as rattlesnake habitat. Rattlers are mostly nocturnal hunters, so be especially alert when night hunting with a headlamp. A rattlesnake can effectively strike up to one-half its body length. Wearing stout boots and snake guards or chaps protect this vulnerable zone. Rattlesnakes are cold blooded, thus when the temperature is hot and the sun is bright, they tend to stay concealed. During the first few hours after sundown they can be found lying on a warm surface such as a road. They have no ears and no hearing. Rather they are very adept at sensing ground vibrations. If you find yourself in heavy brush be sure to snap twigs and stomp your feet, moving slowly to permit concealed snakes to retreat.

     Most rattlesnakes have venom that is primarily hemotoxic [destroys blood cells and skin tissue and causes internal hemorrhaging]. Baby rattlesnakes and the Mojave Rattlesnake ["Mojave Green"] have venom that is primarily neurotoxic [affects ability to breathe, causes irregular heartbeat and is hallucinatory]. Neurotoxins have a much higher fatality potential than hemotoxins. Based on bite statistics, scientists recently have surmised that more and more species of formerly hemotoxic rattlers are becoming more neurotoxic, but are unsure how or why this is happening.

     Experts are nearly unanimous on what NOT to do if bitten: 1. NO ice [more harmful than helpful]. 2. NO tourniquets [could result in loss of limb]. 3. NO incisions [can compound injury and infection]. 4. NO electric shock [still unproved and may exacerbate breathing and heart impairments]. Instead, DO immediately remove rings, watches or tight fitting apparel on bitten limb before swelling starts; wash bite with clean water and soap; keep bitten area immobilized and lower than the heart; immediately seek medical help. Always carry Benadryl with you and take to help ward off anaphylactic shock. If no medical help can be reached within 30 minutes from point of bite, apply a bandage wrapped 2" to 4" above the bite, but NOT so tight as to cut off blood flow. Use a suction device if available [in snake bite kit] or use mouth if no open mouth sores. NOTE: There is a new national poison center emergency phone number -- 1-800-222-1222 [keep it with you for advice on nearest antivenin supply].

     Antivenin neutralizes rattlesnake venom if obtained soon enough. Pets can be inoculated prior to exposure. Dogs also can receive snake avoidance training using live rattlesnakes [in So. Cal. call 1-866-738-6239]. Stupid is as stupid does: 28% of "tease" victims have BAC of over .10%.

Martin H. Milas, PCSC President

(APRIL - 2010)

     For one thing, the ground is eerily silent. It is not unheard of to go up to an hour without a peep from a pulse induction detector. Not much trash to deal with except in the gullies and washes where the old timers discarded their soldered cans, old bottles and tobacco tins. Another weird feature is that the deposition of gold [except for very fine gold] does not conform to any consistent pattern. It is as if some giant shook the entire basin in a blender and then just dumped it all out. Large nuggets of an ounce and over are found as solitaires just like the smaller ones.

     A crazy quilt of surface rights in Gold Basin is privately owned and commingled among BLM tracts. The mineral rights, however, do not run with these private holdings. GPAA and some local clubs have placer claims, but these are few. Thus, there are many camping places throughout the area. Much of Gold Basin is destined for development. In fact, many rough cut roads already have been dozed and numerous survey markers of recent vintage portend a future of new tracts and malls. These may be the final years for prospectors to get some gold. Ocotillos and Joshua trees are cover for scorpions, rattlers and Gila Monsters -- best to wear stout boots and chaps or "Snake Guardz".

     Gold Basin has a lot of fine gold. Some washes have a false bedrock of a shale like material whose fins rise vertically -- perfect for trapping and concentrating flash flood gold. A vacuum and stout bristled brush are a must for cleaning out these natural riffles. A few prospectors use the Gold Exorcist to recover this very fine desert gold. But most utilize conventional drywashers and do very well once the ground dries.

     Gold Basin meteorites typically are of the chondrite type. They range from less than a gram to over a 100 grams. Unlike the smoother surfaced irons found at the Franconia Wash [SW of Kingman], chondrites have small, round chondrules and often have a rusty color pattern. I found two -- a first for me as was the 16 to 18" bright orange and black Gila Monster!!

Martin Milas, PCSC President

(MARCH - 2010)

Getting Fined For Packing Out “Garbage”

     As incredible as it sounds, during the last week of February 2010, a GPAA member was given a fine of several hundred dollars for removing “trash” from Forest Service land adjacent to a GPAA valid claim while metal detecting. This development is alarming and merits a review of federal statutes and federal regulations that pertain to prospecting -- so alarming, in fact, that the PCSC Program for March 2010 will focus in more detail on the blurry and sometimes overlapping lines that separate artifact collecting from gold prospecting and meteorite hunting.

     The facts of the GPAA case, as summarized from a recent Nuggetshooter Forum posting, are rather straightforward: The prospector [“A”] was metal detecting for gold nuggets on open Forest Service land adjacent to a GPAA claim in Arizona. Like most of us do, “A” dug up several pieces of junk consisting of some square nails, bullets, buck shot and other metallic detritus and packed it all out in his pouch. Upon returning to his truck he was confronted by a Forest Service Ranger who proceeded to issue him a citation: $250 for metal detecting on FS land without a permit and $50 for each piece of trash that the ranger determined to be an historic artifact.

     The job of interpreting and applying the relevant laws and rules is not as straightforward as the above referenced facts. What is an historic artifact anyway? There is some federal authority that attempts to draw the line at 50 years. Under this approach literally any object on FS land that is 50 or more years old could be considered protected and removal, or even disturbance of it, without a permit could be considered a citable offense. But who can obtain such a permit and what is the process?

     The mining laws enacted by Congress appear to afford prospectors and claim holders certain rights, protections and exemptions. For example, taking samples and having them assayed would appear to be a self-evident, pre-authorized activity on open federal land prior to staking a claim. But what if, in the process of collecting samples, a person also scrapes up some old bird shot or a boot tack?

     The purpose of this message is to alert PCSC members of a recent instance of a FS ranger who applied antiquities laws to cite a metal detectorist who was on FS land looking for gold nuggets. A more thorough examination of the subject will be made at the March PCSC program. Be sure not to miss it.

Martin H. Milas,  PCSC President

(FEBRUARY - 2010)

Power Steering For Large Pulse Induction Detectors

     Pulse induction [PI] technology permits deeper, more powerful detecting. Minelab is one of the leading manufacturer’s of PI equipment. But, with every design there are some drawbacks. For example, the stock design of Minelab SD or GP series detector requires a virtual monkey dance to mount on one’s body. This is so because these detectors come with a heavy lead acid battery that is carried across the small of one’s back and hips in a pouch on a specially designed harness. The human head is not capable of swiveling 180 degrees like an owl and thus cannot see this clunky battery which also contains one port for a longish curly power cord and another for a headphone jack. In addition to this design shortcoming the PI units are pretty darned heavy and clunky, especially if a large search coil is employed. So, what to do?

     One big improvement is to substitute a modern [approximately one pound] 7.2V lithium ion battery in place of the stock five pound lead acid 6V relic. A wonderful after market device is made by Coiltek [referred to as a “pocket rocket”]. It consists of a voltage regulator which can convert the 7.2V of the lithium ion battery either to 7.3V [for SD series detectors] or to 6.7V [for GP units up to the 3500 model]. A specially designed case permits both battery and regulator to be mounted on the side of the Minelab control unit housing. This unit has a place to insert a headphone jack plus a short power cord to eliminate the long curly cord. Result? No more monkey dance. Your normal human anatomy can see and operate everything very easily. You don’t even need a harness. You now can easily set your PI down out of the way while while you chop out your nugget without interference from the cumbersome curly cord umbilical [which also has a habit of snagging on brush].

     But what about relieving the strain on your rotator cuff? Even with a lightweight battery a Minelab PI is heavy. This problem can be reduced by attaching a bungee cord to your shaft and hooking it to a “D” ring sewn into a lightweight back pack shoulder strap. I use a “Hydro Pack” -- a specialized water carrying back pack with handy pockets. Another clever device is called a “Hipstick”. The bottom clips onto any belt near your front hip. A lightweight rod runs up from this point and snaps onto the D-ring of a harness or back pack. Another fitting allows a bungee cord to hook onto the top of the shaft, thus transferring the entire weight of the suspended metal detector to your hip. It is like power steering -- you feel no weight at all. The coil, no matter how large, just floats wherever you desire. Prospecting is so much more fun with these accessories.

Martin Milas, PCSC President

(JANUARY - 2010)

Vintage Mexican Silver

     Metal detecting occasionally unearths silver jewelry. Some of this jewelry is of Mexican origin. Vintage Mexican jewelry commonly retails between $15 to $50 and as much as $5,000 for rare pieces. Thus, it is useful to know a little about how such jewelry is marked.

     The term “hallmark” is derived from The Goldsmiths’ Hall in London which, in turn, had official authority to mark English gold and silver products since the Middle Ages. In 1530 Mexico, barely a few years after its capture by Cortez from the Aztecs, the Silversmiths’ Guild of Mexico City began requiring all silver pieces to be stamped with a “trademark”. The purpose was to insure quality and to raise revenue. Proof of payment was an official mark [known as the “quinto real” or royal fifth] which was made by a steel punch either hammered or pressed into the piece. Versions of this early system persist into the 20th and 21st centuries.

     In the late 1920s an American craftsman named William P. Spratling was highly influential in establishing silversmithing as an art form in Mexico. He was a contemporary and friend of painter Diego Rivera. Spratling established his “taller” [silversmithing shop] in the late 1920s. He hired local artisans and some foreigners to study and work under him. By 1941 his shop was quite famous and supplied jewelry to Nieman-Marcus, Bonwit Teller and Saks Fifth Avenue. W.W.II cut off sources of gold and silver jewelry from Europe and the Orient. It was during this period that Mexican silver and gold jewelry established itself as a major international supplier. Several of Spratling’s apprentices became masters, established their own tallers and marked their jewelry as their own [e.g., Hector Aguilar, Antonio Pineda, Carmen Beckmann or Margot de Taxco].

     Vintage Mexican Silver bears three types of markings that are useful in dating it. From 1900 to roughly the 20s it was simply marked “Silver” and “Mexico”. In the 1930s and 40s various artisans sometimes also added a logo. From 1948 to 1980 an “Eagle” was stamped on the piece along with a purity number [e.g. “925”] plus a logo. From 1980 to the present a registration system is used. The 1st letter is the location, the 2nd is the 1st letter of the artisan’s last name and the number denotes the order of registration. Thus, a piece marked TC 45 means that it was made in Taxco by a person who was the 45th artist with a last name beginning with a “C” to register in Taxco. Such a piece may also indicate “925” and “MEXICO”. Wash your next find gently with a soft cloth and mild soap. Then, only use a silver polishing cloth [never a dip or a paste].

Martin Milas, PCSC President

(DECEMBER - 2009)

Re-Circulating Sluice Analysis:

     Angus MacKirk manufactures numerous pieces of prospecting and mining equipment of his own design [see www.laurajeanbiz.com]. I purchased and have used his largest re-circulating sluice, the Dry Gulch, sufficiently to allow the following critique:

     Description and Price: Sluice, sluice tray and grizzly are made of lightweight molded, UV resistant, ABS plastic reinforced with a welded, powder coated steel stand assembly. Long steel legs are fitted into the stand assembly and then adjusted as needed. There is no miner’s moss, carpet, expanded metal nor removable riffles. 16 precision molded large and small riffles [similar to a LeTrap] alternate down the sluice’s 22 inch length [6 inch narrowest width]. A 12v 1500 gph bilge pump suspends on a molded hanger to keep the intake a few inches above the bottom of the tub [thus avoiding pump jams]. A hose with an adjustable valve leads to a pair of “water cannons” which maximize material stratification across a goosebumped slick plate draining down into the sluice through a grate. The sluice snuggles in a molded sluice tray and is simple to remove for easy clean outs. No tubs or buckets come with the unit [purchaser supplies his/her own]. The price as of Dec. 2009 is $389.95 plus S/H from Boise, Idaho.

     Pros: The unit is light, collapsible and compact enough to fit inside a 7 gal. cement mixing tub. Precision riffles catch and hold onto the heavies down to fairly fine gold. The flow volume [adjustable up to1500 gph] permits either small scale production runs or concentrate cleanups. The easy clean out features encourage regular concentrate removal. A “boil box” after the last riffle can catch errant flakes. The sluice is cleaned out by tilting it and resting a forward edge inside a gold pan. A second pan can be used to gently flush the gold from one side to the other and then down and out of the sluice into the pan.

     Cons: The grate does not come with a method of capturing all the down rushing material, some of which escapes into the tub [remedied by inserting a small screen]. The steel legs, while stout, can be difficult to adjust -- especially if slightly rusted [remedied by grinding].

     Observations: A fine, well made piece of equipment with better recovery rates and faster than a spiral wheel. Well worth the price. A demo of the Dry Gulch can be made available as an upcoming program.

Martin H. Milas, PCSC President

(NOVEMBER - 2009)

Simple vs. Complex Sluice Designs:

     Traditional stream sluice designs are complex in the sense that they rely on removable riffles, carpet, miner’s moss, expanded metal overlays and/or rubber matting to capture free milling alluvial gold. This complexity is costly in terms of the time and energy required to set one up and clean it out. Little nuts or parts can get jammed by grit or are easily lost. Gold caught in the carpet never can be completely recovered. They also are fairly heavy, employing stout aluminum or sheet metal for the sluiceway and the separate flare [which itself presents potential issues regarding gold losses due to poor alignment or loose fastening]. Clean outs require a bucket or tub in which to rinse the carpet, the riffle bars, the expanded metal screen, the miner’s moss and the bulky sluiceway itself with flare attached and top heavy. Traditional stream sluices catch a much greater volume of concentrates which, in turn, means more energy expended on classifying and panning. Finally, there is the problem of gold losses resulting from the imprecise weldings and slight warpings of the metal riffle bars [which create micro turbulence and eddy currents that can dislodge and carry off fine gold] plus the gap that necessarily exists between the bottoms of the riffle bars and the surface of the sluiceway [beneath which fine gold can escape].

     Modern molded plastic sluices are simple in the sense that there are no parts to deal with, no gaps through which to lose gold, the unit is lighter to carry and the riffles can be machined into the master mold with great precision. Cleaning out is a joy. You just dip the outlet end in a gold pan and then tilt to one side. A turkey baster or cup then is used to carefully pour water along the high side. All the gold and concentrates readily slide to the low side and then down and into the catch pan [no bulky bucket or tub required]. You can visually inspect very easily to insure thoroughness of the clean out. Because of the precision of the moldings, much less black sand winds up in the concentrates. This makes panning out rather easy -- particularly if a small screen like a coffee or tea sieve is employed first to divide the concentrates between plus and minus roughly 20 mesh.

     Because of the cumbersomeness of complex stream sluices, some miners tend to delay clean outs far beyond the capacity of their sluice to retain values, whereas simple plastic sluices encourage frequent clean outs which, in turn, afford valuable recovery information [am I in a good spot or should I move on to somewhere else?]. Comments stated above in regard to stream sluices equally apply to re-circulating sluice designs [an important topic to be addressed in a future “Treasure News” issue].

Martin H. Milas, PCSC President

(OCTOBER - 2009)

Rodent Issues While Prospecting [Part Two -- continued from last month]

     The rats held back their attack and I was able to emerge safely back into the sunlit world I am familiar with. I vowed never again to get myself into such a situation. But, of course, the scent of gold always can change perceptions as well as promises.

     My closest encounter with rat packs took place, not on a claim, but on the largest duck ranch west of the Mississippi which at one time stretched for over two miles along the 605 Freeway. It was the late 1970’s when my friend, the foreman at the ranch, first asked me to help with a rat disaster of monstrous proportions -- a true and gruesome story of being attacked by hundreds and thousands of rats gone crazy, best saved for the telling over a campfire or at a later time; perhaps at the upcoming PCSC outing on the weekend of October 24 - 25. I only mention this to help explain why I lost a lot of sleep one night at the Red Chispa claim.

     The Red Chispa has resident rat colonies. Mostly you never notice them and they leave you alone. There are exceptions. One moonlit night in 2003 I was sleeping in the bed of my F-150 pickup at a time when it had a tonneau cover. The tonneau was up and the tailgate was down. I was lying in a sleeping bag with my head snuggled in a down pillow resting aft on the extended tailgate, my legs stretching to the cab. I wrestled with a dream in which something was jostling my sleeping bag. I remember kicking my feet and then half awakening to a lot of squeaks and tearing noises. A shot of adrenaline brought me to full, heart pounding consciousness as I rolled over to see what was causing the commotion.

     There beside me, not more than 24 inches from my face, at least a dozen or more rats were scrambling to bail off the edge of the tailgate. They were panicked because the huge, sleeping giant was waking up and their tiny claws were getting stuck in the velcro-like carpet liner of the truck bed! Oh my, did they ever squeal and squeak. Finally they all managed to jump off into the night, albeit without the loot they had come for -- a roll of paper towels. Big chunks that had been bitten out of the roll lay abandoned on the truck bed along the route of their exodus. Three days later when I returned home I discovered that a large nest had been constructed atop my V-8 engine. It contained creosote twigs and black plastic wire insulation material. From this I learned always to warm my engine at least five or ten minutes a day to discourage such wire chewing and nest building. Aside from gnawing, desert rats may harbor serious diseases. Leave them alone and keep food packed in stout containers.

Martin H. Milas, PCSC President

(SEPTEMBER - 2009)

Rodent Issues While Prospecting [Part One]

     The desert has many different rodents that prospectors must deal with. Pack rat stories are legendary. One of the common scenarios involves the theft of small objects which sometimes are replaced with an exchange item such as a small nut or some seeds. See, for example, Bob Dunkin's story that appears in the PCSC web site ["Bill McHaney And The Mountain"]. In my case I've had some memorable encounters that I'd rather never happened. The first took place on the PCSC Clark claim. The second, even closer, encounter was at the Red Chispa a year or two later.    
     One day Jim Sharp and I decided to explore a "coyote hole" that we had uncovered. We were following a 6" to 10" pay layer of cemented, smooth cobbles about 13 feet below surface that carried a rich sprinkling of gold. Jim is short and pneumatic. He was able to wiggle over and around boulders that had detached and caved in over the decades from the unreinforced overhead. In my case I had to literally pull and tug at my own ankles to contort and squeeze my 6'2" frame rock by rock into the depths of the tunnel. After 15 minutes we had advanced maybe 40 feet when we came to a compartment large enough for both of us to fit side by side. Another sharp bend then took the tunnel to the left. Rattlesnakes, of course, are a common danger in these confines. But I wasn't prepared for what was lying in wait for us around that corner. It was a wall of pure green creosote vegetation!! We realized at once that we were face to face with a huge rat colony that could at any moment decide to rush us en masse. Jim and I hurriedly scooped up samples and as soon as our buckets were full we tried to retreat as gracefully as we could. Short, loose-limbed Jim was out in minutes, but I got stuck due age related stiffness and a cramp in my thigh muscles. The air had become intolerably fetid. It carried the heavy, acrid odor of rat urine and rat feces. This was their world and I had invaded their turf. Numerous times I spanked and pounded at my thigh to relax the cramp. But I also slapped my own psyche mercilessly for having been so foolish in the first place. Here I was, stuck in an old tunnel dug more than a century earlier that was in an obvious state of decomposition and collapse. It was an impossible 13 feet straight up through heavy overburden to reach the surface or a miserable crawl through another 30 feet of jumbled boulders, some precariously hanging from a ceiling which, in turn was only 18 to 24 inches high. And the rats were probably sensing that I was trapped. I could hear a dry rustling and crackling of creosote material somewhere in the darkness behind me. Suddenly the gold didn't seem so important... [continued next month]

Martin H. Milas, PCSC President

(AUGUST - 2009)

Ascertaining Melt Values

     Precious metals are, of course, precious. But precisely how precious is any given nugget, ring or coin? What is the so-called bottom line? The precious metals industry refers to this as the melt value, i.e., the monetary value of the elemental metals. The computation of melt values requires knowing the following variables: 1. Spot price (the most recent monetary value of a given metal per the New York, London or World Markets at any time of any day), 2. weight of item (usually in Troy units or in grams) and 3. purity of item (expressed in karats).

     Troy units are based on a Troy ounce ("OT"). There are 12 OT to a Troy pound. One OT consists of 20 pennyweights ("dwt") or 480 grains ("gr"). One OT also is equivalent to 31.1 grams ("g"). Gold (Au), silver (Ag) and platinum (Pt) are listed on commodity exchanges in Troy weights.

     Pure gold is marked 24 karats (24K) or 1.000 fine. Gold and silver jewelry is required by most international laws to be marked for purity. This can take different forms. The composition of gold jewelry is expressed as a ratio of the percentage of gold to pure gold. Thus, a 10K ring has ten parts of gold out of 24 parts, or 10/24ths pure. An 18K ring is 18/24ths pure. A sterling silver ring typically is marked .925 or 92.5 (92.5% pure silver). The various national mints that issue silver coins typically publish the purity in terms of its silver composition, e.g., a Mercury Dime is .900 silver and .100 copper. It weighs 2.5 grams. Thus, it is .07234 oz. pure Ag.

     A handy formula will enable you to figure out the current value of the gold in an object. 1. Look up the spot value of an oz. of (say) gold. Let’s say it is $900. 2. Multiply this amount times the fraction resulting from the ratio of the actual dwt weight of the object to the total dwt in an OT. Let’s say you have found a 10 dwt gold ring. The fraction of 10 dwt/20 dwt is 1/2. So in step two you multiply $900 times 1/2 = $450. 3. Multiply the result of step two times the fraction resulting from the ratio of the stated purity of your gold ring to total purity. Thus, if your ring is marked 12K, then the fraction of 12/24 (or 1/2) results. To complete step three multiply $450 X 1/2 = 225. The ring you found has a melt value of $225.

     The complete formula of the above is: Spot per OT X [actual dwt divided by total dwt/OT] X [purity of object (K) divided by 24K] = Melt Value.Thus, $900 X 10/20 X 12/24 = $225. Homework assignment: What is the melt value of a one dwt natural gold nugget found on our Red Chispa claim? Hint: The gold runs roughly 22K at the Red Chispa.

Martin H. Milas, PCSC President

(JULY - 2009)

Ergonomic Tips For The Older Prospector

     Bad back, bad knees, bad shoulder, bad neck. We all suffer these types of aches and pains, but the older prospector does not recover as quickly. The following are some observations that may be helpful.

     Drywashing: Always try to minimize peak joint loads. Two gallon buckets are easier to hoist than five gallons (note: a level full 5 gal bucket of typical desert dirt weighs about 70 lbs. A 2 gal bucket weighs just 28 lbs). When lifting a bucket or any heavy object keep it as close to your body as possible (elbows tucked next to ribs) and learn to completely contract your abs and squat low prior to the lift. Avoid twisty movements while under load (rather than twist at the waist, use your feet to turn your entire body, keeping your vertebral column as straight as possible). Mix up your movements. Repetitive shoveling, picking or raking inflames older joints by causing bone spurs to rub against each other on the same spots. Take many brief stretch breaks (place hands on hips or in back pockets while arching backwards to loosen up tight back muscles, then stretch neck upwards and afterward tilt head from side to side -- BUT NOT to the point it hurts! This is important. Only stretch to the point where you can begin to feel pain, then quickly back off). Miner’s elbow (the opposite of tennis elbow) can benefit by extending your arm stiff at the elbow and horizontally outward from your side while flattening your outstretched palm against the side of a tree or your truck. Then lean into it, but not past the point where it begins to hurt your inner elbow area.

     Metal Detecting: Rotator cuff pain is exacerbated by rapid, jerky back and forth swings. Stress can be relieved by slowing down, holding the shaft closer to your body and by the use of a HipStick (a device that transfers the load from your rotator cuff to your hip). If you feel a "kink" during your swing, this may be a bone spur catching. Try to flex your shoulder into a position that avoids this kink (otherwise you may cause the bone spur to grow so big it could require surgical removal). Knee pain can be relieved by wearing good quality knee pads and by not spending more time than necessary on your knee (for example, by using a Hermit Pick or similar long handled scraper to first isolate your target out of the hole).

     Beach Detecting: Wet sand is heavy. Avoid stress to wrist by using a curved scoop shaft (so when you lift or pull the scoop your wrist is unbent). Avoid a scoop that is too large. Keep your elbow extended as you haul back on a heavy load. Let your legs do the work. A bent elbow will result in Miner’s Elbow (pain in the inner portion of elbow). When shaking the sand from the scoop keep your elbow and wrist stiff and close to your ribs. If near the water, let the water wash away the wet sand. Bill Samarin will demonstrate his alternative to a heavy scoop at the July meeting. This may proof to be an ergonomically superior tool.

     Dredging: Invest in a swivel nozzle that has a horizontal handle so that while you are controlling the intake your wrist is not bent. When clearing large cobbles and rocks try to move them first into a metal bucket underwater. Then drift the full metal bucket underwater to your dump zone. Avoid chucking rocks into the air. Some folks use an inflatable float to ferry a tub of large cobbles to a dump zone. Use a small lead or steel flat weight (like a small barbell weight) on your chest to calibrate your float position over the dredge zone (this avoids neck and shoulder stress and keeps your face close to the nuggets). Contract abs and squat prior to standing up when wearing heavy weight belts.

     Nugget Shooting: Walking for miles up and down gullies in the desert takes a toll on hips, knees and ankles. Stretching PRIOR to your search is key to reducing pains. Two good stretches are: (1) bend your knee against a tree or your truck while you extend the other leg straight back. Then stretch hard until you feel it just begin to hurt in your calf. Hold position for about 30 seconds. Switch to other knee. Do at least 2 or 3 reps. (2) Sit in a chair and extend one leg at a time. Flex foot backwards until you feel it begin to hurt in your calf area. Then maintain position for 30 seconds while pumping foot back and forward. Do 2 to 3 reps.

     At The End Of The Day: Take the time to relax and stretch. A good way I do this is to lie on my back with my legs hooked over a chair seat. I place softly inflated plastic balls (the size of softballs) under my lower back. I roll up a towel and place under my neck. Then I stretch my back backwards and keep it stretched by wedging the towel under my neck. I then relax my facial tension and my abs until I can breathe all the way out effortlessly. I meditate and get into a "zone". I get more mileage out of this simple practice than any of the other methods. Folks with special problems should consult a physical therapist. Many tips are available on-line.
Martin H. Milas, PCSC President

(JUNE - 2009)

     Heat is a high risk hazard for those over 65, who are overweight, who take certain meds, who recently have over eaten or consumed alcohol or who overly exert themselves during hot weather. Once your internal body temperature reaches 106F the proteins of your brain begin an irreversible transformation process (similar to frying an egg white).

     Tips to prevent and/or treat heat exhaustion and heat stroke while prospecting: Always take at least a small ice chest full of ice and at least a 1 or 2 gallon ice filled water jug (in addition to regular water supply). Pre-freeze some water bottles. Drink a cup of cold water every 15 minutes whether you are thirsty or not. I pre-scatter several water bottles in the area I am metal detecting or raking so I do not have to carry the weight, but I then have access to frequent water. Work early in the morning or during the night with a headlamp. Take a chair and a beach umbrella and take frequent breaks. Wear a loose fitting, disposable white cotton dress shirt (from second hand store) buttoned only in 2 or 3 places. Saturate your hat and the shirt often (just pour water over shoulders, under arm pits and down front and back) Do not bother with aerosol sprays as they are inadequate. Use a buddy system. Watch each other for symptoms. Eat very sparingly, but do consume salty things. Potassium tablets are good. Carry a cell phone or 2-way radio. Start out slow and pace yourself.

Martin H. Milas, PCSC President

(MAY - 2009)

Tip For Working Black Sands And Sulfides

     This tip was shared with me by PCSC member Ray Garcia. It may enable you to recover much more than just the initial visible gold. I pass it on to you in my own modified, step-by-step format:

1. Screen your black sands to minus 20 or 30 (ie, all that will pass through a #20 or a #30 classifier).

2. Place a load in your tumbler (best to use a rubber tumbler tank). Add ordinary cider vinegar (or citric acid) instead of water. Then run tumbler for 10-12 hours. Empty tumbler, store resulting tumbled concentrates aside and then repeat with new batches until all black sands have been through the tumbling process.

3. When finished, thoroughly flush the dissolved iron (it looks like brown clay or mud) with tap water to clean the resulting mass of concentrates.

4. Now, screen those cleaned up concentrates through #50 and #100 classifiers (result: 3 groups; plus 50, minus 50 and minus 100).

5. Run each group through a gold bowl properly adjusted for each run (see my earlier article on how to adjust bowl velocity for differing sizes of sand concentrates).

6. Remove the visible gold after each run (with a pipette or snuffer) but save the black sands (save ONLY the black sands that remain in the bowl -- not the lighter material that was drawn down the vortex). Some of these remaining heavy black sands are likely to contain sulfide gold.

7. Mix these remaining black sands with an equal part of ordinary table salt (ie, sodium chloride).

8. Place in an iron skillet, DO NOT cover, and heat outdoors and down wind until very dry and very hot, stirring occasionally. The heating accelerates the breakdown of sulfide gold on contact with oxygen in the atmosphere. Avoid breathing vapors and do not use this skillet for cooking food. Large iron skillets often can be obtained at low cost in thrift stores, garage sales or estate sales.

9. Pour contents of skillet while still really hot (but not the skillet) into a tub of cold water (this fractures the sulfide gold free from encapsulating material). It might be a good idea to use a de-chlorinating agent to first remove the chlorine from the cold water prior to quenching the concentrates.

10. Re-classify all of this fractured material and run it through bowl as described above in steps 4 - 6, using a pipette or snuffer to isolate and capture the "now visible" gold.

Martin H. Milas, PCSC President

(APRIL - 2009)

Maximizing Metal Detector Performance
   
     A metal detector's performance can mean the difference between getting that elusive nugget or smelling the skunk. There are several ways to insure that your detector is functioning at its best. Let's start with the connections. Depending on a detector's design, there are one or more connections that can act as "pinch points" to the flow of electrical currents. One must pay close attention when connecting the search coil wire to the detector box. The terminals are subjected to dust and vibration and need to be kept clean and tight, otherwise unnecessary resistance will diminish the quality of the signals and a scratchy "noise" may develop. On the Minelab SD and GP series, it is recommended that the terminals be cleaned regularly by using a small pipecleaner anointed with a touch of WD40. The pipecleaner then is inserted into each of the "female" recepticals and the matching prongs are given the same vigorous cleaning. If you are unsure of your hand and finger strength it may be advisable to utilize a small pair of pliers to make the final snug-up when tightening. But be careful not to overdue it.

     Maintaining peak voltage is especially important in the PI machines which consume much more energy than the VLFs. The Minelabs in particular are at their best when the voltage is at its peak. The SD and GP series use 6 volt batteries, but in reality the GPs run at 6.8 volts and the SDs at 7.3. Just as your automobile battery is rated at 12 volts, at peak charge it actually is substantially higher. The 6V Minelab wall outlet chargers apparently are designed to top out at exactly 6V, whereas the cigarette lighter 12V adaptor charger will top the battery out to the peak voltage. In recent years a product known as the "Pocket Rocket" enables you to strap a lithium ion battery to your control box and a regulator insures that peak voltage is maintained.

     Wrapping the search coil wire snugly around the "stick" prevents the wire from flopping around and inducing phanthom signals known as "falsing". This is especially important on highly sensitive gold machines like the Minelab PIs. Note that some after market coil manufacturers, such as Coiltek, make falsing difficult to control because of an apparent design flaw in which the wire exits from the coil way off center, far from the shaft. Thus, no matter how tightly you wrap the wire there still is a section of wire that will brush against or snag on obstructions such as creosote branches that are abundant in the desert. Nugget Finder coils are made with the wire exiting the coil very near to the shaft. Paying attention to keeping the wire tightly wrapped near the control box also will reduce falsing.

Martin H. Milas, PCSC President

(MARCH - 2009)

Paying Attention To Moisture Can Pay Off

     The more moisture in the dirt, the less effective a drywasher becomes -- particularly when the riffle tray is maintained at a shallow angle. Why is this so? Adhesion refers to a molecular force exerted between the surfaces of physical bodies that are in contact with one another. Example -- glued surfaces or a shoe sole on a sidewalk. Cohesion is a related, but distinct concept. It refers to a type of molecular attraction that unites individual particles throughout a larger body. Example -- a droplet of water or a clump of damp soil. The degree of each of these forces can be influenced by the presence or absence of moisture. Likewise, these forces can be overcome if more powerful kinetic forces are applied. When drywashing, it is of the utmost importance to run material that is extremely dry. Otherwise the particles of gold will be subjected to increased forces of adhesion and cohesion and possibly carried off with the header and tail matrix. This especially will occur if the riffle tray is not set steeply enough. By flattening the riffle tray, you minimize velocity, i.e., you decrease the amount of kinetic energy available to separate the cohered particles.

     But how can I tell if the dirt is dry enough? One of PCSC’s eminent members was Arthur Clark (who quitclaimed the Clark Claim to PCSC). Art spent many years experimenting with different soils. He also designed, built and sold his own line of drywashers along with nearly a hundred different riffle configurations. I have all this information in Art’s unpublished treatise (a copy recently was auctioned at PCSC for about $15 -- quite a buy!). It was Art Clark’s conclusion that soil with more than a 3% by weight of moisture content should not be run.

     To determine for yourself precise moisture content, take a representative volume of soil and carefully weigh it. Then, transfer this entire volume to a suitable cooking or baking container. After thoroughly heating the material at a high temperature (sufficient to drive off virtually all moisture), then carefully weigh the material again and calculate the percent of weight that was water. Example: You start out with 100 ounces of soil. After cooking off the moisture you reweigh it and now it only weighs 97 ounces [97/100=x/100 or 97% of the original weight, therefore moisture constituted 3% of original sample].

     How else can I tell if the dirt is dry enough to run? An experienced miner can make a crude guess by taking a handful of dirt and squeezing it as hard as he can. If it clumps in the least degree it is too moist. Another way is by observing the dust that results from tossing a handful in the air.

Martin H. Milas, PCSC President

(FEBRUARY - 2009)

Cleaning Out A Patch With A Metal Detector

     Once a patch has been located, the next task is to clean it out. But, how best to do this? Using a labor intensive drywasher fairly insures that most of the gold will be recovered. Unfortunately, a good patch typically is fairly large; too large to clean out in a single day or even on a single weekend, given the limitations that drywashing entails. Additionally, not all patches contain a sufficient concentration of fines to warrant drywashing. Finally, the patch may be located in a place where others can move in on your digs unless you have sufficient time to sit on your spot until it is thoroughly cleaned out -- not a luxury of time that most of us possess. An alternative to drywashing is the use of metal detectors in conjunction with a few common garden tools.   

     Typically a patch will occur on a hillside. I use gravity by first estimating the most downhill edge of the patch. At this point I use a rake to clear a level terrace surface (about 18" X 5') by raking off the loose stones and loosening the soil down to about 2 or 3 inches. A VLF metal detector with a small search coil then is swept over this leveled spot directly into the surface dirt. After recovering trash (and perhaps nuggets), I then use a hoe to draw the loose material back down hill until I am back to a hard surface. Then this is raked and broken up again down to 2 or 3 inches, checked by my detector and hoed off. I repeat this terracing until I reach a level where no more trash and no more nuggets are detectable with the VLF. After scraping off for the final time I run my PI detector over the surface to insure that nothing is hiding beyond VLF range.

     The next step is to move immediately uphill to fashion a second terrace step, back filling onto the first level as I go. And then so on and so forth until the patch is cleared out. In this way I am expending energy most economically, recovering virtually any gold that is too large to pass through a #20 classifier (as small as flyspeck in size and sub-grain in weight) and restoring the surface to the original contour of the hillside. I don't have to inhale dust or make a racket with a gasoline engine. Nor do I have to haul bulky, cumbersome machines that may require a truck or large SUV. And it doesn't matter if the soil is damp. In short, this is a very thrifty way to explore for gold and exploit the ground.

     My technique does require considerable physical exertion and can be hard on the neck and lower back. When in the desert I generally limit my terracing efforts to the cooler mornings and evenings, spending the warmer midday hours hunting afield with the PI unit.

Martin Milas, PCSC President   

(JANUARY-2009)

A Sampling Plan Using A Metal Detector

     Establishing a grid, digging dirt, screening it down and panning it out is not the only way to sample a desert area. An alternative strategy involves a smaller and completely different set of tools and can cover a larger area more quickly. Instead of a bulky battery powered spiral wheel, many gallons of water, buckets, a shovel and classifiers, I sometimes employ just a garden rake and a lightweight metal detector. Here is how I go about it.

    The basic idea is that a sensitive VHF detector with a small search coil can find surprisingly small pieces of gold. I call these micro nuggets. Unlike the traditional nugget definition of any gold that will not pass through a number ten classifier, micro nuggets occupy the niche between what will pass through a number 12 but not through a number 20. Gold of this size is more common than larger pieces and is an indicator of larger gold.

    By flattening and smoothing the surface with a garden rake I am able to make direct contact between my search coil and the dirt. This is important because micro nuggets can not be detected if more than an inch or so distant from a search coil and the really, really tiny ones are virtually undetectable unless they actually make contact with the search coil. Longtime PCSC member Dean Chapman once pointed out to me that the best places to use a VLF are slopes or ridges long exposed to wind erosion. This is so because the wind already has blown away substantial overburden. The resulting matrix is thus heavily littered with stones and rocks not far from bedrock and may contain a concentration of nuggets (ie, a "patch"). But how best to utilize your energy?

    Consider two factors. First, much eluvial gold has been released from veins and veinlets of quartz. These veins are narrow in width but stretch for rather long distances. Therefore, unless severely altered by tectonic movements or major water flow, the patches that result over the eons from said veins tend to mimic the shape of the original birthing vein. Second, it takes less energy to rake gravels once than it takes to rake the same gravel two or more times. Okay, now let's put these principles to work.

    Instead of clearing a large square area, why not clear the same amount of surface material in the shape of a long, extended line? Example: A 10' X 10' square contains 100 sq. ft. But in order to clear such a space, I would have to rake and re-rake the same gravels and stones many times. Now compare this effort to creating instead a swath 50' long and 2' wide which also exposes 100 sq. ft. of surface area. Much less effort involved! I only rake the gravels once. Now consider this: What is the probability of a 50' swath intersecting a longish, narrow patch of nuggets as opposed to a 10' X 10' shape accomplishing the same? Obviously, a long line has more chance of crossing another longish line.  Finally, it now is time to go home. What is easier to restore -- a long, narrow swath or a square shaped patch containing the same amount of surface area? That's right! In no time I can restore the desert surface and cover my tracks by re-raking the edges of a 50' X 2' swath together a whole lot easier than a big square patch of surface disturbance.

    There are more details and labor saving tips in regard to sampling with a metal detector. Such as the concept of scalping, the use of gravity, exploiting old digs and ideas regarding better and worse detectors and coils. These will have to await future discussion.

Martin H. Milas, PCSC President

(DECEMBER - 2008)

A Basic Sampling Strategy

    Digging and shoveling desert dirt is hard work. If I am going to invest my time and effort, I want to maximize the likelihood of a return. So, what follows is a description of a fairly basic sampling strategy for determining the best place to dig. I first utilized this methodology on the PCSC Red Chispa claim. That particular claim has a definite productive zone that runs roughly diagonally from northwest to southeast. The zone varies from around 50 feet to 200 feet in width. Not much is found outside the zone. And absolutely nothing at all is found in over 50% of the claim's total area. This is how I went about it over a period of several trips.

    First, I learned from others where gold was known to have been found. Second, I noted where the largest concentrations of very old cans were concentrated. Then I selected a promising hillside. I made a drawing of the wash. Then I dug a number of holes and classified the material down to minus 8. I filled 2 gallon buckets with this sample dirt, labeling each one and marking the locations on my drawing. Then I ran each bucket of material through an 18" Gold Magic spiral wheel. I panned out the concentrates from each run and counted the colors. In addition to the color count, I also wrote notations on my drawing as to the relative size and texture of the colors.

    As noted, this testing spanned several separate trips. I was careful always to dig when not being observed. And I always would remember to cover over my dig holes and tracks. Why? Because the Red Chispa has many, many looky-loos. If they think you have found a sweet spot, they will descend on it when you are not there and clean it out. The idea, in other words, is to pinpoint your sweet spot, keep it a secret and then wait until you have a string of around five days straight when YOU can camp on top of it, clean it out, and leave nothing for others.

    Now I have a Pro Camel 24 spiral wheel. It can process a lot more dirt a lot faster. I also have developed more efficient ways to classify material. And I go to remote areas with no looky-loos. Thus, I now can perform a fairly thorough sampling job in a single day or two and then set up a production hole all on the same trip. Without a sampling plan, it is just hit or miss luck of the draw whether you come home with good color. With such a plan, less time is wasted shoveling barren dirt. A similar sampling strategy can be performed with a metal detector. More on that subject in a later issue.

(NOVEMBER - 2008)

<Coin & Ring Tips & Comments   

     Each February the PCSC Annual Awards Banquet has brought us together -- not just to recognize the individual contributions of all who serve this club so well -- but also to enjoy an evening of camaraderie and good food.   Chuck and Chris Carfrae have been among the great club stalwarts over the years who take the laboring oar.  And once again they made this a high point in our social calendar despite a serious medical setback for Chuck who had to sit this banquet out.  We missed you, Chuck, and we wish you a speedy recovery.

Martin H. Milas, PCSC President

     Looks like our February meeting will be the place you want to be if you ever wondered what hard rock mining is all about.  Bob Dunkin grew up in Twentynine Palms.  On his sixth birthday his father informed him that it was time to learn about gold mining and took him underground on a tour of the Gypsy Queen, one of the area’s still productive mines in the early 1950’s.  The gold bug bit him hard and ever since that day Bob has chased the yellow metal close to his home in the Dale Mining District and as far afield as Alaska.  He has owned and operated his own mines, was in the process finally of making a fortune and then lost it all in legal fees fighting the government.  Needless to say, he is a great source of information and is a wonderful story teller.  I promise that you will not want to miss this one!  Best of all I have recruited Bob to join our Club.  In the event the Club is interested in picking up some additional claims, he could be a valuable asset.   Know the difference between a hanging wall and a foot wall?  Know why this is important?  No?  Well, be sure to bring these or other questions.  I’m sure that Bob will oblige you with answers that only can come from over 50 years of intense experience of handling dynamite, dealing with rattlesnakes and maybe most scary of all, dealing with our own government.

Martin H. Milas, PCSC President

Tide Activity

We have some big tides rolling through Southern California in February.   The series of big swings begins around Valentine’s Day and progresses into high (or should I say “low”) gear at 12:40PM the day of our annual awards ceremony and dinner (Feb. 16th).  The next four days in a row the high tides will be running around 6 feet plus in the mornings, then draining back out for lows of -1.3 feet occurring between 1 and 3 in the afternoon.  Sooo...if luck is with us, maybe some or all of those days we will also get some big wave action -- especially with periods of 8 seconds or less.  These are the conditions that can make for metal detecting heaven -- as long as you don’t get caught in a rip!  I for one plan to be ready for action.

 Martin H. Milas, PCSC President

Classified Ads

     How many of you would like to add a classified ad section to our Club website?  A place you can post a "want to buy" or "want to sell" ad?  For free.   Let’s talk about this at the February meeting.  If enough interest is shown, then we can make it happen.  This and other suggested ideas will be discussed after the program during the "new business" portion of the meeting.

Martin H. Milas, PCSC President