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Collecting Native Silver & Related Minerals in Northeastern Ontario’s Silverfields Introduction… I’ve been cleaning and photographing some small native silver specimens that were found with a metal detector during my last few rockhounding visits to the silverfields of northeastern Ontario. They are commonplace examples of small silver that hobbyists can anticipate recovering from the tailing disposal areas of abandoned minesites, ranging in size from one-half to several troy ounces. The information and silver photos presented below may interest newcomers to the fascinating hobby of rock, gem and mineral collecting, particularly for those who have reasonable access to collecting sites for native silver and associated minerals such as the example displayed below. It is comprised primarily of rich, dendritic acanthite with some minor inclusions of native silver visible on the surface. Searching for Small Silver… When selecting an appropriate prospecting-capable metal detector for this application, consider the field conditions where you will be operating it. A large portion of your time will involve searching abandoned minesite tailing disposal areas because these sites offer you the best opportunity to find native silver and related minerals. (a) At many sites ferromagnetic susceptible substrates can be characterized as ranging from light to moderate, and will have little effect on a VLF detector’s ability to function effectively. But some areas, for example diabase dominant substrates, exhibit more elevated magnetic susceptibilities that to some extent will reduce a VLF metal detector’s detection depth and sensitivity, target ID accuracy, and discrimination reliability. The effects of harsh ground mineralization can be somewhat mitigated by operating a VLF metal detector in a true motion all-metal mode to maximize detection depth and sensitivity to targets. A smaller / DD coil will reduce the ground mineral footprint scanned by the detector, permitting the use of higher gain / sensitivity levels than would otherwise be possible. Regardless of target ID or the absence of it, ensure that all weak signals are investigated until the source is identified. An obvious alternative strategy to improve detection depth is to use a suitable PI detector for searching more difficult ferromagnetic ground mineral areas. A more recent Minelab PI model will ensure the best possible detection depth over such ground. (b) Consider the most frequent size of the silver you can expect to find with a metal detector. The small silver depicted in the accompanying photos is representative, and as noted above, range from about one-half to several troy ounces. They are typically larger coin-size targets detectable to very good depths, but keep in mind when choosing a suitable prospecting-capable VLF detector that most small silver is low conductive, and on average is characterized by a nickel target ID. (c) In some areas conductive pyrrhotite hotrocks are a real nuisance to both VLF and to PI detectors. Abundant pyrrhotite can render specific sites unsuitable for metal detecting. Target ID ranges from iron to low foil, with most pyrrhotite signals eliminated by upper iron range discrimination. My PI units, the Garrett Infinium and White’s TDI Pro, both generate enticing low conductive signals to solidly structured pyrrhotite, and similar to small, low conductive native silver, pyrrhotite PI signals must be dug. (d) Mining country, and abandoned mining camps in particular, are littered with iron trash of all sizes and description. Small, low conductive iron signals can be eliminated with suitable VLF iron range discrimination, but most non-descript small iron produces low conductive signals from my PI units. Similar to pyrrhotite, our PI units cannot reliably distinguish low conductive silver from low conductive ferrous trash. All low conductive PI signals therefore must be dug, and to do so is prudent fieldcraft regardless which PI brand or model is utilized for this detector-prospecting application. Incidentally, the same observation largely applies to VLF target ID reliability over deeper, weak target signals in more difficult ferromagnetic substrate conditions. Such signals tend to produce questionable readouts that either frequent or reside within the iron target ID range. To have any confidence in VLF target ID, it is necessary to remove surface material from deeper target signals until a reasonably strong VLF detection signal can be obtained. If any doubt about target ID remains, dig it to be absolutely certain of its identity. By comparison to low conductive iron, big compact iron such as larger drill bits and milling balls, and sizeable elongated iron such as broken pipes and implements, rail spikes, and drill rods tend to VLF target ID in the non-ferrous range. My PI units produce high conductive signals to large compact iron. A similar response, usually a double low-high or single low-high-low signal, is produced as the coil is swept lengthwise on elongated iron, whereas low conductive signals are normally produced when the coil is swept across the length of such targets. With native silver’s variable conductive potential (variations in size, shape, purity, structure) quite capable of producing both high and low conductive PI signals, the foregoing explains why all PI signals should be identified. While a large portion of our fieldwork in the northeastern Ontario silverfields is more suitably addressed with VLF units, we frequently use a ground-balancing PI unit for general scanning over tough ferromagnetic substrates where ferrous trash levels are tolerable. In these conditions we employ larger coils to improve detection depth over what VLF units can achieve. Additionally, our PI units eliminate or reduce most non-conductive iron-mineralized hotrock signals in the area. Such signals can be a particular nuisance when searching diabase dominant substrates with a VLF unit. Our VLF preference is to use mid-operating frequency range detectors for this application. Mid-frequency units respond reasonably well to both high and low conductive silver, and to weaker signals produced by low conductive particulate and sponge silver. By comparison to high frequency units such as my Goldbug2 for example, they are less vulnerable to elevated ferromagnetic mineralizations, and see both higher conductive targets and larger targets at better depths. Incidentally, low operating frequency units work reasonably well, but are less sensitive to low conductives. We operate both the mid-frequency White’s MXT and Fisher F75 for motion all-metal mode close-up scanning involved with removing surface material from hillslopes, trenching, sinking testholes, and for detecting excessively trashy areas requiring a discrimination mode, but there are other perfectly acceptable detectors that will perform well at these tasks. Your detector choice ideally should feature a target ID in a threshold-based motion all-metal mode, a discrimination mode, include a manually adjustable full range ground balance, a “fastgrab” ground balance for convenience and to assist with target signal evaluation, and a selection of searchcoil types and sizes. Which type of metal detector is best suited for this application? We operate the PI and VLF units described above to deal with variable field conditions and objectives, but the VLFs do much of the fieldwork here. Newcomers should begin with a VLF unit that incorporates the features outlined above as a minimum. You may wish to supplement your stock coil with larger and smaller coils to increase your versatility in the field. Once you have gained some field experience with the conditions as described above, and generally have learned more about collecting silver minerals, you can make a more informed decision as to whether acquiring a suitable prospecting-capable PI unit is a viable choice to satisfy your objectives in the field. Where to Look for Silver & Other Minerals… As a general principle regardless of the type of minerals one seeks, successful collecting invariably depends on knowing where to look and a willingness to do serious pick and shovel work. Surprisingly detailed information about where to search for many minerals is readily available online to hobby newcomers, with many collecting sites readily accessible by personal vehicle. On occasion, more remote sites or identified prospects will typically require a short hike. For example, extensive information about abandoned gold and silver mines can be accessed online, and many current government publications are available to interested hobbyists. My personal favorites include a series entitled Rocks and Minerals for the Collector authored by Ann P. Sabrina, in association with the Geological Survey of Canada. These publications supply practical, useful information pertaining to abandoned minesites throughout Canada. They provide road guides to accessible collecting locations, a brief history of a site’s mining operations, normally include production numbers for more prominent minerals such as cobalt, lead, zinc, nickel, copper, silver and gold, and usually provide a comprehensive list of mineral occurrences for each site. For casual or recreational prospecting enthusiasts visiting this area with limited time to search for silver ores and nuggets, select abandoned sites that will more likely produce detectable native silver based on past production numbers. You can detect these sites with the certain knowledge that highgrade silver was inadvertently discarded to the tailing disposal and nearby areas, sometimes in considerable quantity. The probability of successfully recovering specimen grade silver is sharply improved compared to searching for outback silver float, obscure prospects, or low production sites. To improve the likelihood of finding silver, try to identify areas where valuable silver was handled and transported. For example, look for evidence of surface veins, shafts, and storage areas where silver was graded, moved, and sometimes inadvertently misplaced. There are many plainly visible field indications of former mine buildings, mill sites, ore transport routes and abandoned trails. While quantities of silver were frequently discarded to tailing disposal areas, keep in mind that some highgrade silver was unknowingly included with waste rock for road and other construction projects. Hobbyists have also detected large specimen grade silver that was occasionally lost to spills on steep embankments, washouts, or sharp bends along the transport routes of the time. Incidentally, we occasionally see examples of careless or halfhearted retrieval techniques when only a few more inches of digging in tough ground would have unearthed quality silver that produced unmistakably solid, tight non-ferrous target signals that could not be mistaken for iron trash. A general suggestion to newcomers is to be thorough in all aspects of your fieldwork, examine abandoned digsites, and dig all questionable target signals until the target is identified. Briefly About Acanthite… As a related but slight diversion from the topic of searching for small native silver, depicted below is a small but massively structured example of acanthite / native silver recovered from the Kerr Lake area of northeastern Ontario. While selecting some reasonably photogenic small silver examples, I decided to include it here because valuable acanthite https://www.minfind.com/minsearch-10.html recoveries are a rather infrequent occurrence in my personal experience and therefore welcome additions to my collection. After some 30+ prospecting seasons, I’ve never detected acanthite as a stand-alone mineral. My acanthite finds have always contained some detectable native silver. For those unfamiliar with this mineral, acanthite is a dark silver sulfide (Ag2S) approximately comprised of 87% silver and 13% sulfur. Smithsonian Rocks & Minerals describe it as the most important ore of silver. Much of the world’s current silver demand is satisfied as a by-product from the refining of argentiferous (silver-bearing) galena. Galena, a lead sulfide, generally contains some small (< 1%) amount of silver in the form of microscopic acanthite inclusions as an impurity. Acanthite is occasionally misidentified as argentite by hobbyists, but the correct mineral classification when referring to silver sulfide (Ag2S) at room temperatures is acanthite. Both these silver minerals possess the same chemistry but different crystalline structures. Argentite forms in the cubic (aka isometric) system at temperatures above 177 degrees Centigrade (temperature slightly varies according to reference source). Below that temperature acanthite is the stable form of silver sulfide, and crystallizes in the monoclinic system (Smithsonian Rocks & Minerals 2012 American Edition, Eyewitness Rocks & Minerals 1992 American Edition, Wikipedia). The transformation of argentite to acanthite at lower temperatures often distorts the crystals to unrecognizable shapes, but some retain an overall cubic crystalline shape. Such crystals are called pseudomorphs (false shapes) because they are actually acanthite crystals in the shape of argentite crystals. Acanthite crystals frequently group together to form attractive dendritic (branching) structures embedded in light-hued carbonate rocks that range from rather intricate to massive. In the field, try to be visually alert to darker (typically sooty-black) acanthite that may be exposed while digging targets, trenching, or by chance encounters with recently exposed material. For example, the local township occasionally removes tons of tailings for road and other construction projects, resulting in fresh new surfaces for hobbyists to explore. Prominent Minerals Associated with Native Silver… Native silver, acanthite, pyrargyrite and proustite ruby silvers, stephanite, and other collectable silver minerals primarily occur in carbonate veins in association with gangue minerals such as quartz, chlorite, fluorite, barite, albite, hematite, magnetite and many other minerals related to relatively shallow epithermal deposits. Attractively structured native silver embedded in light-hued carbonates, or for example in association with other silver minerals such as acanthite and proustite, is highly valued by the mineral collecting community. For newcomers incidentally, structure refers to how the silver is formed, examples include massive or nuggety formations, plate, disseminate or particulate, sponge, highly crystalline, and various dendritic or branching patterns as illustrated by the native silver example in the multi-photo below. The native silver in this area is intimately associated with major cobalt-nickel arsenide deposits that include notables or collectibles such as safflorite, cobaltite, nickeline, and skutterudite. A number of these ores, typically arsenides and sulfides, produce perfectly good signals from VLF metal detectors. Solidly structured nickeline (aka niccolite), a nickel arsenide, is a fine example that can generate strong signals from both VLF and PI metal detectors. Moreover, it is not unusual for rockhounders to find surface examples of nickeline with its copper-green surface oxidation annabergite, and cobaltite displaying its pink-to-more infrequent reddish surface oxidation erythrite as depicted below. A wide variety of additional minerals can be collected from the mine dumps. These include more localized occurrences, for example, allargentum (silver antimonide), titanite (wedge-shaped, vitreous calcium titanium silicate formerly called sphene), native bismuth, chrysotile serpentine (asbestos), rutile (titanium oxide) and breithauptite (nickel antimonide), to more commonplace minerals such as sphalerite, arsenopyrite, chalcopyrite, bornite, galena, marcasite, iron pyrite, and so forth. A Final Word… In closing we should point out to interested readers that there has been a resurgence in active exploration for both diamonds and cobaltite minerals in the northeastern Ontario silverfields. The existence of diamonds has been widely known for years, and historically there has been a strong industrial demand for cobaltite for hardening steels and other alloys, paint, ceramic, and glass pigmentation, and in other various chemical manufacturing processes. Apparently now there is increased interest in cobaltite for the manufacture of batteries. Industrial demand notwithstanding, for many years cobaltite has also attracted hobbyists interested in recovering valuable crystals. I hope that both experienced mineral collectors and hobby newcomers have enjoyed reading about native silver and a few of the more prominent associated minerals in this area. Thanks for spending some time here, good luck with your rock and mineral collecting adventures, perhaps one day it will be our good luck to meet you in the field. Jim Hemmingway, October, 2019

Abandoned Trails in Silver Country Introduction… Silver country represents a small part of a vast, heavily forested wilderness perched on the sprawling Precambrian Shield here in northeastern Ontario. Away from the small towns and villages, and widely scattered farms and rural homesteads, there exists a largely uninterrupted way of life in the more remote areas. There are uncounted miles of lonely country backroads, overgrown tracks leading to abandoned mining camps, innumerable rough timber lanes, and a virtually infinite tangle of winding trails that reach deeply into the distant forests. Nothing in my experience has been so completely companionable as the soft forest whisperings and the beckoning solitude that reigns over this ruggedly beautiful country. This is where my carefree days of autumn prospecting have been agreeably spent for many years. We returned again this year to unbounded, satisfying autumn days of kicking rocks, exploring and detector-prospecting adventures, followed by evenings spent evaluating silver ores while savoring hot coffee over blazing campfires. Irrespective of silver recoveries, the flaming autumn colors of the boreal forest are the real treasure of the season. They persist for only a few short weeks, reluctantly yielding to the autumnal yellows of the tamarack, birch, and aspen in sharp contrast to the deep conifer greens. Scenery as depicted below accentuates your enthusiasm to get into the field, and pretty much ensures that an autumn prospecting trip to silver country is a memorable experience. General Discussion… Unprecedented, persistently wet conditions eliminated any potential for a banner season, but nonetheless we did manage to find considerable worthwhile silver. In addition to an assortment of rich silver and associated minerals, my friend and occasional partner Sheldon Ward recovered a large, very high conductive native silver ore that we’ll take a closer look at shortly. Most of my quality silver finds were fairly small, although a specimen grade silver ore at five pounds was found during the final week of the trip, and frankly I felt very fortunate to get it. Larger material was recovered, for example a 24-pound highgrade silver ore from the same area, but these invariably were mixed ores co-dominated by cobalt and various arsenides, most notably niccolite as illustrated below. On a more positive note, we both found plentiful small silver generally ranging between one-half and ten ounces that added real weight to the orebag over the season’s duration. It is much easier to find small but rich, high character silver than is the case with larger material. Even so, specimen grade detectable silver in any size range is becoming increasingly difficult to find at many of the obvious, readily accessible sites nowadays. The photo below is a pretty fair representation of the overall quality, although anything below a half-oz was excluded from this shot… such are not terribly photogenic beside larger samples. Some rich ‘nuggety’ ores were HCl acid-bathed to free the silver from carbonate rock, and all samples were subjected to a rotary tool circular wire brush to remove surface residues, followed by a dish detergent wash and rinse. By way of a brief background explanation to readers unfamiliar with this prospecting application, we search for more valuable coin-size and larger pieces of silver. Natural native silver target ID is determined by physical and chemical factors such as silver purity, types of mineral inclusions, structure (for example, dendritic, plate, disseminate or particulate, sponge, nuggety or massive), size, shape, and the profile presented to the coil. Virtually all natural silver from this area will target ID from low foil up to a maximum of silver dime range. Only infrequently over the years have we found isolated, rare examples of our naturally occurring silver exceeding that range. The specimen depicted below is a commonplace example of silver typically recovered here. It isn’t terribly large or particularly handsome, but it is mostly comprised of native silver by weight. Its target ID is a bit elevated from the usual, but consider that even small changes to some of the more influential factors listed above can significantly alter target ID. I tend to pay minimal attention to it when evaluating samples. It was detected adjacent to an abandoned mining track that leads directly to a former mill site at the mining camp scene depicted above. No treatment required other than a leather glove rubdown followed by a soapy wash and rinse, in fact it looked quite presentable fresh out of the dirt. The darker material you see is heavily tarnished native silver that I intend to leave undisturbed. Ground conditions also play an important role in determining target ID, and refer to factors such as the strength of non-conductive magnetic susceptible iron minerals present, ground moisture content, proximity of adjacent targets, and disturbed ground. These factors sometimes contribute to good silver at depth producing a VLF target ID within the iron range. Probably the best photo example available to me is a specimen found a few years back at good depth in tough magnetic susceptible diabase. It produced a predominantly iron target ID on the Fisher F75. It was detected in a fairly low trash area, the signal was suspect, and it was checked with the groundgrab feature. In this instance, there was no ground phase reduction to more conductive values as would be anticipated over rusty iron or a positive hotrock, and so the target was dug. The general rule of thumb over questionable weaker signals, regardless of groundgrab results, is to remove some material to acquire a stronger signal and target ID readout before making a decision to continue digging in our difficult, hard-packed rocky substrates, or to move on. If there is the least doubt, we dig the target to learn what actually produced the signal. The specimen depicted below was found by eyesight while hiking along an old abandoned rail track. In the field our rock samples seem more attractive or valuable than they do once we return to camp, where we tend to view them far more critically. If they don’t look to have good specimen grade potential, my samples are either abandoned in an obvious place for others to find, or given away to visitors back at camp. But that’s just me, most hobbyists are more resourceful with unwanted samples, they’re refined by some, subjected to treatments, or slabbed, and ultimately sold. In any case, this rock didn’t terribly impress me and was placed with other discards on the picnic table. But nobody other than my wife seemed much interested in it, and that is how it came to be included here. In its original condition, it could only be described as nondescript, with very little showing on the surface prior to treatment. It did produce a broad solid PI signal, despite that the few surface indicators were non-conductive dark ruby silver pyrargyrite and to a much lesser extent what I suspect is the black silver sulfosalt stephanite. To see more, it was acid-washed to expose silver and associated minerals, cleaned-up with a rotary tool, followed by a dish detergent bath and clean water rinse. Both these minerals produce a good luster that makes them a bit more difficult to distinguish from native silver in a photo. But in reality it is easy to see the differences and do some simple tests to confirm if necessary. The acid treatment revealed that the sample does have a good showing of dendritic native silver, a timely reminder that metal detectors see what we initially can’t see inside rocks. Abandoned Trails, Minesite Tracks and Roadbeds… Abandoned, frequently overgrown trails, mining tracks, and roadbeds provide convenient routes to prime detecting sites that otherwise would be much more difficult to access. But the important thing is that most such routes were built with discarded mine tailings to considerable depth, and contain good silver more frequently than you might think possible. Some snake through the bush to more remote areas, but the vast majority of these now abandoned routes were built to service existing minesites at the time. They were used to transport discarded rock to the tailing disposal areas, and silver ores to storage buildings and to mill sites, and generally to service other mining camp requirements. We know from research and experience that silver was misgraded, inadvertently misplaced, or lost directly from spills to eventually reside on, within, or alongside these now abandoned trails and roadbeds. These mine tailings… frequently containing rich silver… were also used to build storage beds, minesite entrances, loading ramps, and as noted… routes to facilitate waste rock transport. All these offer excellent, obvious prospects to search with a suitable metal detector. The nugget below, with several other pieces, was found in the tailings adjacent to the abandoned track in the photo above. Some good weather following a horrendous week of persistent heavy rainfalls prompted me to head out late one afternoon for some casual detecting. I had sampled those tailings earlier in the season but nothing by way of thorough searching. And while the silver was generally small, it had been surprisingly good quality. So I was looking forward to a few relaxing hours of detecting… nothing ambitious that late in the day… just happy to get out of camp. That particular spot formerly housed silver storage beds, and was now replete with large rusty nails. I should have used a VLF unit, as things would have gone much more quickly. VLF motion all-metal detection depth in that moderate ferromagnetic substrate would pretty well match Infinium equipped with the 8” mono, with the further advantage of target ID and groundgrab features to assist with signal evaluation. If conductive pyrrhotite hotrocks had also been present, I would have switched over to my F75 or MXT to take advantage of target ID. But I stayed with the Infinium primarily because I enjoy using it. By comparison it is slow going, but that isn’t such a bad thing over potentially good ground. It silences what can be described as VLF ground noise, in addition to sizable non-conductive mafic hotrocks in this area. It also has some limited high conductive iron handling capability, for example elongated iron such as drillrods or rail spikes at depth that VLF units using iron discrimination modes misidentify with perfectly good signals and non-ferrous target ID readouts. More information on this subject can be found at… http://forum.treasurenet.com/index.php/topic,384975.0.html http://forum.treasurenet.com/index.php/topic,385640.0.html Nearly all the signals proved to be nails, plus one drillrod with a perpendicular profile to the coil. The silver below produced a low-high signal in zero discrimination and a good high-low signal in reverse discrimination (maximum available pulse delay setting) at maybe eight to ten inches depth. The exposed silver was unusually tarnished and the remainder partially embedded in carbonate rock. It was acid-bathed to free the silver, cleaned with a rotary tool silicon carbide bit and circular wire brush, followed by a detergent wash and rinse. While searching one such abandoned route with his Fisher F75 equipped with the stock 11” DD elliptical coil, Sheldon Ward found a large highgrade silver ore comprised of a thick calcite vein containing massive dendritic native silver. The vein material weighs about 25 lbs, and was attached to a mafic host rock. It generated a moderate but broad signal from several feet depth, requiring an hour of hard pick and shovel work to recover it. It possesses an unusually elevated target ID in the silver quarter range. After 30+ years searching this area recovering numerous silver ores and nuggets, I've seen only a small handful of silver produce a similar target ID. On site we obviously have the benefit of closely examining the vein material, but it’s more difficult for readers to evaluate the silver based on photos only. Outdoor photos do tend to make native silver look much like grey rock, and unfortunately this one is smudged with dirt. I’ve added an indoor photo from Sheldon that displays the vein material after it was separated from the host rock and cleaned. Sheldon if you happen to be reading along here, congratulations on your many superb silver and associated mineral recoveries over the past year. Nothing that your dedication and persistence achieves in the years to come will ever surprise me. WTG!!! Persistence Pays Dividends… Let’s wrap things up with a tale about the rock sample below. It was recovered at the edge of a tangled overgrown trail near a former millsite just a few years ago. Its recovery exemplifies that the more you work towards your objective of finding silver or gold, the more likely your probability of success will correspondingly improve. I’d been searching that particular area for two days without meaningful results while evaluating a newly purchased Garrett Infinium for this application. The second day had again been filled with digging hard-packed rocky substrates for iron junk, worthless or otherwise unwanted arsenides, and plenty of conductive pyrrhotite hotrocks. As the sun was reaching for the western horizon, I decided to make one final effort before heading elsewhere the following day. Methodically working along the old track towards the mill, lots of old diggings were plainly visible. But previous hunters had ignored an area with a scattering of large, flat rusty iron pieces and other miscellaneous modern trash. I moved quickly to clear it away, because daylight was fading fast beneath the dense forest canopy. My Infinium soon produced a surprisingly strong high-low signal that practically vanished in reverse discrimination… a promising indication of naturally occurring ores. I dug down a foot before my Propointer could locate the signal. Probability says that it could have been any number of possible targets altogether more likely than good silver. But fickle Lady Luck was more kindly disposed towards me that evening. The rich, finely dendritic piece depicted below was in my gloved hands just as twilight was stealing across that lonely abandoned trail in remote silver country. A Final Word… A special mention to my friend Dr. Jim Eckert. I hadn’t seen much of Jim recently, but happened across his trail late one overcast afternoon in the outback. I was about to hike into a site when this fellow came flying down the trail on a motorbike, and despite the riding helmet I recognized him. We had a good long chat about this and that… Later in the season, one bright sunny afternoon at the site of my short-lived testhole diggings, Jim stopped around to show me a recent specimen find comprised of native silver and crystalline stephanite. We talked mineralogy and other interests many hours until finally the sun was going down. These were highlights of the trip, and I want to say how much I enjoyed and appreciated having that companionable time together. Thanks to everyone for dropping by. We hope that you enjoy presentations about naturally occurring native silver, particularly since it is different from what many rockhunters normally encounter in their areas. All the very best with your prospecting adventures… perhaps one day it will be our good luck to meet you in the field…………………… Jim. Reposted July 2018 Detector Prospector “Rocks, Minerals & Gems”