Silver is one of the seven planetary metals (gold, silver, mercury, copper, lead, iron and tin) known by the ancients, to each of which the alchemists assigned the influence of a planet: silver was dominated by the moon.
The alchemists named the metal Luna or Diana, and denoted it with the figure of a crescent moon; the name has survived in lunar caustic, silver nitrate. Silver nitrate or silver sulphide was blended with pipe clay and applied to (usually) clear glass to create the silver stain seen in medieval stained glass. This painting technique was utilised in order to obtain a varied palette without having to cut and join different colours together with lead strips. Silver chlorides change on exposure to light, this reaction being the basis for black-and-white photography. The first recorded use of silver as a colour name in English was in 1481.
Silver occurs in nature in ores and as a free metal; the chief ores are sulphides, from which the metal is extracted by smelting with lead. It has been mined since prehistory. Archaeological excavation e.g. at Mt. Laurion by Edouard Ardaillon (Mines du Laurion dans l'antiquité, Paris 1897) provides some evidence of lead and silver smelting. Silver mines such as Potosi, in Bolivia, were for many years a source of wealth for Spain. Father Jose De Acosta in his Historia Natural y Moral de las Indias, published in 1590, describes the use of the amalgamation process in the extraction of silver at the Potosi mines.