Gold is the mostly highly prized of all metals. Its bright yellow glitter and malleability has made it, since the dawn of history, the metal most treasured. The earliest craftspeople used gold to fashion decorative pieces of all kinds. In the Middle Ages, artisans were trained as goldsmiths to create jewelry and ornaments of the highest order, some surpassing work done by the craftsmen of today.
Gold found in its native state is rarely pure 24k, but is usually associated with silver and often with mercury. In its natural state of pure gold, the substance is very malleable and can be hammered into very thin sheets. When the silver content is a high percentage of a naturally-occuring gold mass, the metal is called electrum, a natural alloy. Gold is also found in tellurides and ore containing quartz wherein it is either visible, or enclosed in particles of sulfide minerals such as chalcopyrite, pyrrhotite, pyrite, and arsenopyrite. In some high-production gold mines, the gold is not visible and can be seen only on a highly polished surface when viewed through a high- powered microscope.
Gold has no oxides and is not affected by oxygen in the atmosphere as are other metals. This is why gold does not tarnish -- tarnish is the result of metal reacting with oxygen in a process called oxidation. Gold is malleable to the point that it can be hammered into a leaf or sheet of foil 3/1,000,000 inch thick (0.000003 inches) on an area approximately 6 square feet. The thin sheet is translucent and transmits a greenish light through the leaf.
