Silver has been known by humans since prehistoric times, and its discovery is estimated to have happened shortly after that of copper and gold. One of the earliest reference to the element appears in the book of Genesis (13, 2). The Egyptians considered gold to be a perfect metal, and gave it the symbol of a circle. Since silver was the closest to gold in perfection, it was depicted as a semi-circle. Later this semi-circle led to a growing moon symbol, presumably due to the likeness between the shining metal and the moon glow. The Romans called silver argentum, and we keep this alive by retaining Ag as the chemical symbol for this element.

Silver, like gold, was considered by the Ancients as an almost sacred metal and consequently, it had extremely restricted use. Because of its malleability and ductility it was easily worked and this, coupled with the lustre, made it ideal for ornamental purposes. It was also used for paying debts, for decoration in religious places, as utensils in the wealthiest houses and, of course, for personal adornment. Silver ornaments and decorations have been found in royal tombs throughout the world dating back as far as 4000 BCE.

Some mineral slags from old mines in the near-East and from some islands of the Aegean Sea reveal that, by 5000 BCE, a method was already known to extract silver from lead ore. The silver mines worked by the Carthaginians in Spain were well known and Roman envy of this wealth helped to bring about the Punic Wars.

With such a long history, few people are unaware of silver. Most peopleís knowledge stretches to knowing that it is a precious metal and it is mined. But where is it found, and how does it occur? Names such as Silver City in New Mexico (where Billy the Kid spent his early years and where Apollo 17 astronaut and geologist Harrison 'Jack' Schmitt grew up), Silverton, NSW, Australia (where some Castlemain xxxx beer advertisments were made and where Mad Max strutted his stuff) and our own (Scottish) Silver Glen near Alva, openly testify to the occurrence of nearby silver. Other localities are less obvious but are of no lesser importance and there are few countries throughout the world where silver is not found. We are familiar with the appearance of silver in jewellery but how does it look in its unprocessed state?

There are 248 mineral species that contain silver as an essential component. Very very few names give an indication that the mineral contains silver. Minerals such as argentite (Ag2S) and the more obscure argentocuproaurite ((Cu,Ag)3Au) obviously indicate a silver content but what of eskimoite (Ag7Pb10Bi15S36) and vikingite (Pb5Ag2Bi6S15) and the almost unpronounceable uchucchacuaite (oo-chew-cha-co-a-ite for those willing to try) (AgMnPb3Sb5S12). These last three belong to the sulphosalt category.

Eskimoite and vikingite are named in honour of the peoples associated with Greenland as the minerals were discovered at Ivigtut, Greenland. Uchucchacuaite is named after its discovery locality at the Uchucchacua mine, Oyon, Cajatambo, Peru.

ësulphosaltsí is the longstanding problem in mineralogy. Although the term ësulphosaltsí has long been in use, no generally accepted definition exists up to now. In chemistry, sulphosalts (thiosalts) are known as derivatives of sulphoacids (thioacids) [H3(AsS3), H3(SbS3), H3(BiS3) etc]. In a broad sense, sulphosalts are regarded in mineralogy as compounds of metals and semi-metals with sulphur, which can be partially replaced by Se, rarely by Cl and O. The general formula commonly accepted for these minerals is AmBnXp, where: A are metallic elements, usually Pb, Ag and Cu and less frequently Zn, Hg, Tl etc., B are semi-metallic (formally trivalent) elements As, Sb and Bi (partly Te4+) only, X is S, partly Se, more rarely Cl.