Book VIII metals, precious such as gold, platinum, silver Page 182



	170	DE NATURA FOSSILIUM

	These large masses of gold may be found free of rock or attached to it. The very tenuous foils of gold that have a sparkling luster are always attached to marble, rock, stones, gems, etc., and may be worn away from these by the force of water (for this reason they are called ramentum) and carried away by streams and rivers. Aurum in its native form is called airvpos by the Greeks, i.e., not recovered by fire while gold that has been heated and separated from the admixed silver is called άττ€φθο$. The latter is also called obryzus according to one writer. Gold containing silver is called "argentiferous by the Latins, Xevkos, by the Greeks because of its white color. Pure gold is yellow with a distinctive brilliance and a unique and extraordinary natural luster. It melts in a fire and can be cast but the melting has so little effect upon it that it can be separated from all other metals and still lose none of its volume. It is improved and purified by heating it repeatedly for long periods in a broad shallow vessel until it glows with the color of fire. For this reason it has always been regarded as the most precious metal. Since it is acrid other acrid minerals such as salt, soda, vinegar, juice squeezed from unripe grapes, etc. will not dissolve it nor reduce its volume as does the water made from atramentum sutorium that separates gold from silver. It contains no impurities such as rust or verdigris. When rubbed on the hands it leaves no filth as do other metals which proves that it is naturally pure. Nothing comes off the pure metal. It will not make a mark of its own or any other color and in this way can be distinguished from all other substances of similar appearance. It will only make a mark when rubbed on a touchstone (coticula), a mark that is similar to its color. It is softer than silver and hence if a ring made from white gold or electrum³ is worn day after day on the same finger with a ring made of pure gold the latter will eventually wear away completely. Although gold is soft it is not fragile. It can be hammered so thin that fifty or more foils such as artisans use, approximately four and one-half inches on the side, can be made from about five ounces of gold. This foil is only one-third as thick as that used by pharmacists and painters. Gold can be drawn into thread either with or without silken wool. Sometimes this thread is woven. Gold has about the same weight as lead⁴ and neither metal produces any distinctive sound when struck or thrown. Many objects other than coins are made from gold. I will discuss the latter in De Precio Metallorum et Monetis. The former are created as ornaments for man and his temples as well as for other purposes. For ornaments man uses rings, bracelets, brooches, earrings, necklaces, hollow spheres, chains, crowns, and cicadae⁶ which, since they are worn by the Athenians, are called τίττίΎοφόρας. Temples are decorated with golden statues such ^! Filings or scale. ⁵ A silver-gold alloy that may contain up to 20% silver. * Gold is 69% heavier than lead. ⁵ A gold insignia made in the form of a cicada and worn in the hair.