Article reprinted with permission and originally appeared in the May Issue of the NYMC Bulletin - http://www.newyorkmineralogicalclub.org/
“It’s Elemental” is a series of columns by Bill Shelton written this in year in recognition of the United Nations’ International Year of the Periodic Table of Chemical Elements.
Here we will find two metals that are especially easy to find if you wish to purchase a sample for an element collection. Now, silver as bullion coins or bars are instantly available if you think you want to own one. Bismuth is very easy to find as man-made hopper-like crystals with rainbow colors. I see them all the time at major shows and expect you could find them on the internet. I used Google and found bismuth for sale as both ingots and crystals. That’s good news for element collectors.
On the periodic table, silver is number 47 and it is located near the middle of period five. In rank order, silver is number 67 meaning 66 out of 92 naturally occurring elements are more common than silver. Contrast this with bismuth which is element number 83. It is located in period six next to lead. You will find it right of center and near the bottom of the main part of the periodic table. It is number 64 in rank order so we see that elemental rarity is very similar for this pair. About three quarters of the 92 natural elements are more common in the earth’s crust.
You might wonder why the symbols for some elements clearly match their names, i.e., Bi for bismuth while a few others such as Ag for silver do not. Well, silver is part of a group of elements that have been known for a very long time. In this case, the name is based on the Latin term argentum; hence the symbol Ag. Bismuth was first noted around 1,500 years ago while silver is present in ancient artifacts and mining is known from 3,000 years ago. Ancient Sumer is thought to be the source of the oldest silver artifact dating to about 4,000 BC. Sumer is located in modern-day Iraq. So, in terms of the 92 natural elements bismuth ranks among the first fifteen to be recognized while silver is among the first ten – all known before 1,000 BC. In fact, silver may have been known as long ago as 5,000 BC.
Mineral collectors are likely to come across bismuth and silver because a few species with these elements present as major components are relatively common both on the internet and at mineral shows like the next NY shows on March 2nd and 3rd or June 22nd and 23rd in 2019. Dana’s Textbook, 1966, tells us there are 22 species of note for bismuth and emphasizes bismuthinite and native bismuth as perhaps the most frequent examples one might encounter. Also, silver has 55 species and the most common ones are argentite and native silver. Acanthite is also important and you may wish to seek more data regarding this species because it may be used to refer to species once called argentite. Using data from Mindat.org, it appears that we can find 187 species that contain silver and 233 with bismuth present. As a note to collectors, many of these are not likely to be interesting to you.
My experience makes me suspect silver species are far more desired and sought out by collectors than bismuth examples. Some additional silver-rick species that I notice in museum collections, personal collections and the mineral marketplace are listed below.
Proustite, pyrargyrite, polybasite and stephanite are four additional examples that seem to get a fair amount of attention from collectors. To a lesser extent, I find amalgam, dyscrasite, stromeyerite, andorite and cerargyrite. Since natural examples exist for bismuth and silver, you can add them to a collection of native elements. There are about twenty different possibilities that I believe you can locate with little effort. In aesthetic terms, silver may be among the five or so examples that are most popular – I base this on what is present on internet sales sites, museum collections, private collections and the illustrations in books and magazines.