Gold has had an inestimable effect on human history. It has been crafted, mined, worshipped, plundered, fought over and traded for thousands of years. Today, the search for gold is as eager as ever, despite the vast stocks stored away in underground bunkers. So why has gold held this fascination for humanity?
Pure, or 24-carat gold, is the brightest yellow, but as the amount of silver increases the color becomes paler. Pale gold containing more than 20 per cent silver (corresponding to about 20-carat gold or less) has been called electrum. Trace amounts of copper, iron and palladium can also substitute in gold. Man-made alloys of gold with rhodium, iridium or palladium, intended to give gold greater hardness when used in jewelry, have been given names such as ‘white gold’. The carat scale is commonly used in jewelry, while in mining, an alternative scale uses ‘fineness’ of gold, where a figure of 1000 corresponds to pure or 24-carat gold. Credits: By Dr Bill Birch, Senior Curator, Geosciences, Museum Victoria