Detecting for Natural Metallic Silver

I recently received an email inquiry regarding the purchase of native silver specimens. While I have none to sell, I thought this might be a good topic to examine for Treasure Talk. Few metal detector operators have ever hunted for native metallic silver, but it does exist.  Most newly mined silver is extracted from silver bearing minerals that will not sound off on a detector, but natural metallic silver will certainly trigger a metal detector if the pieces are large enough. While native silver is not an uncommon mineral in silver deposits, it often occurs as small irregular flakes, wires and masses disseminated through the vein, and the pieces are often so small as to be invisible to a metal detector and nearly invisible to the eye without the help of magnification.

On the other hand, large masses of silver do sometimes occur and I think these situations are largely overlooked by the average prospector out with his metal detector looking for a good find. These larger specimens can come in strange, twisted and contorted forms of wires and crystals, though sometimes they are found as blobs of silver looking very similar to nuggets of gold, but with the wrong color. The wire and crystalline specimens can fetch very high prices from mineral collectors - potentially worth their weight in gold. Natural metallic silver is colored silver - white when clean, but is readily tarnished. Because of this, metallic silver specimens will often come out of the ground in gray to black colors of tarnish. So if you detect a mass of black wires or scales, don't toss it aside as waste! It is not advisable to clean them, especially if your goal is to sell them. I've included some photos so you can see what this type of native silver looks like.

This twisted mass of silver wires is a common form of native silver. This specimen is from Norway. 

Native silver is ordinarily a product of near surface weathering, so it is secondary in its origin, having been derived by the chemical reduction of silver sulfides or other silver-bearing minerals on exposure to air and water. In some districts it is among the most valuable ore minerals, but it commonly occurs as tiny flakes or thin sheets plastered on the older minerals or as veinlets filling cracks in the ore. It is only when the pieces are large enough that they are of interest to the prospector armed with a metal detector.

This mass of silver wires is formed in more of a herringbone pattern of crystal growth. It is from a silver mine in Mexico. 

Native silver has been found in the United States with native copper in the copper mines of the Lake Superior region; in crystal groups at the Elkhorn Mine in Montana and as large masses in the silver mines of Aspen, Colorado. Native silver is also found in a number of locations in Arizona and Nevada. Silver is found in large quantities as platy masses, associated with various cobalt and nickel minerals, at Cobalt, Ontario, Canada. This is the one location where I know metal detectors are regularly used to find metallic silver. Natural silver is also an important element in silver ore from the mines of Chihuahua, Guanajuato, Durango, Sinaloa and Sonora in Mexico. Native silver is also common in some of the silver mines of Peru. Silver has been found in large and beautiful specimens in the mines at Kongsberg in Norway, including masses up to 500 pounds in weight.

This inter-grown silver and copper specimen is from the great lakes region of Michigan. It is well crystallized and was offered for sale at a mineral show in Tucson at a price more than its weight in gold. 

I have included a photo of a native specimen displayed at the Tucson Gem and mineral show a few years back which weighs nearly 20 pounds and goes by the name of the "Silver Dog". It shows that native silver can be pretty big and spectacular. This piece was found with a Minelab metal detector a few years back in the Serrita Mountains of Arizona. I hunted in the Serrita Mountains once, but didn't find any silver or gold. The USA is the world's third largest silver producer, but Australia is ranked as fourth, supplying approximately 10 per cent of world's silver production and I've seen some good native silver specimens from Australia. Native silver has been found in small specks and filaments at St Arnaud, Glendhu and Omeo in Victoria state. Australia has also produced natural silver from occurrences at the Elura Mine, Cobar, and at Broken Hill, both in New South Wales. I've also seen interesting silver specimens from China and several locations in Africa.

This large silver specimen is from the type that looks more like a typical gold nugget in its rough and irregular shape. It is quite large, weighing in at just a little less than 20 pounds. 

Minelab's detectors designed for gold prospecting make excellent choices for silver detecting, especially the GPZ 7000 and the SDC 2300, both of which are very sensitive to wire and irregularly shaped metal. I've never found any native silver with a metal detector myself, though it's one of the things I've always wanted to do. I was researching through some old mining reports recently and came across a reference to an old silver mine that supposedly produced nice silver specimens when it was worked in the 1800s. I think I will give it a try this year when the weather warms. Most Nevada mines that contain native silver produced it only in small pieces - little flakes and wires. Not much of that stuff would make a decent specimen and would not likely be visible to a metal detector, but I did find that note in the old report. So call it a new year's resolution, in 2017, I will take my Minelab metal detectors out and use them searching for native, metallic silver.