Nitric acid is used for testing up to 10k gold, and gold finer than 10k gold will only react with a mixture of nitric and hydrochloric acids known as aqua regia. Alloys of Gold Mixtures of gold with such metals as copper, silver, zinc, etc. To analyze a metal to determine its purity. Au The chemical symbol for gold, from aurum, the Latin word for gold, derived from Aurora, the goddess of shining dawn. Bullion Gold which is at least 995 fine.
Bullion is available in the form of ingots, bars, or wafers.
Casting The process of duplicating an object by pouring molten metal into a hollow mold that has been made of the original object or model. In lost wax casting, used in jewellery production, molten gold is forced under pressure into a mold from which the wax model has been burned out. Chasing A highly skilled and ancient art of decorating metal with figures or ornamental patterns, which may be either raised or indented. The work is done entirely by hand without mechanical aids. The modern chaser draws out the design on the surface of the metal and delineates it with a hammer and punches, not removing metal, as is done in engraving, but pushing it aside.