Precious metal alloys

thumb|Natural electrum "wires" on quartz, historic specimen from the old Smuggler-Union Mine, Telluride, Colorado, USA thumb|The Pactolus river, from which [[Lydia obtained electrum for its early coinage]] thumb|Electrum Phoenician metal bowls|Phoenician bowl with mythological scenes, a sphinx frieze and the repre­sentation of a king vanquishing his enemies, Cypro-Archaic I, from [[Idalion, 8th–7th centuries BC (Louvre, Paris)]] thumb|Brooch with a griffin protome, from the necropolis of [[Kameiros, Rhodes, (Louvre)]]

an alloy of a precious metal (most commonly silver, but also gold) with a majority base metal content (such as copper)

Orichalcum (or aurichalcum) or orichalc is a metal mentioned in several ancient writings, including the story of Atlantis in the Critias of Plato. Within the dialogue, Critias (460–403 BC) says that orichalcum had been considered second only to gold in value and had been found and mined in many parts of Atlantis in ancient times, but that by Critias's own time, orichalcum was known only by name.

alloy of gold and at least one white metal, usually nickel, manganese or palladium

thumb|right|300px|Diptych with Nativity and Adoration, silver and niello, [[gilt-bronze frame, Paris, , The Cloisters]] thumb|Byzantine gold ring with niello inscription: "Lord help Leontius, Patrician and Count of imperial Obsikion guarded by God", Niello is a black mixture, usually of sulphur, copper, silver, and lead, used as an inlay on engraved or etched metal, especially silver. It is added as a powder or paste, then fired until it melts or at least softens, and flows or is pushed into engraved lines in the metal. It hardens and blackens when cool, and the niello on the flat surface is

alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper

thumb|Funeral mask in Tumbaga - Lambayeque culture Musée des Amériques

various colours of gold obtained by alloying gold with other elements

thumb|Osmiridium-564562 Osmiridium and iridosmine are natural alloys of the elements osmium and iridium, with traces of other platinum-group metals.

thumb|Unpatinated shakudō Shakudō (赤銅) is a Japanese billon of gold and copper (typically 4–10% gold, 96–90% copper), one of the irogane class of colored metals, which can be treated to develop a black, or sometimes indigo, patina, resembling lacquer. Unpatinated shakudō visually resembles bronze; the dark color is induced by the niiro artificial patination process, involving boiling in a solution, generally including rokushō.

thumb|French ormolu mantel clock (around 1800) by Julien Béliard (1758 – died after 1806), Paris. The clock case by Claude Galle (1758–1815) Ormolu (; ) is the gilding technique of applying finely ground, high-carat gold–mercury amalgam to an object of bronze, and objects finished in this way. The mercury is driven off in a kiln, leaving behind a gold coating. The French refer to this technique as ; in English, it is known as gilt bronze. Around 1830, legislation in France outlawed the use of mercury for health reasons, though use continued to the 1900s.

thumb|right|Japanese_sword_mountings#Components|Kashira made of dark-finished shibuichi, with gold highlights

thumb|A murti statuette of [[Vishnu made from Panchaloha]] Panchaloha (), also called Pañcadhātu (), is a term for traditional five-metal alloys of sacred significance, used for making Hindu temple murti and jewellery.

highly valuable metal alloy in classical antiquity

thumb|300px|BSE images of PGMs forming polymineralic aggregates - Platarsite and rutheniridosmine

In numismatics, potin is a base metal alloy used in coins. It is typically a mixture of copper, tin and lead (in varying proportions) and does not typically contain significant precious metals. Potin is usually used in reference to Celtic and Ancient Indian coinage.

thumb | right | Bowl made of Corinthium Bronze Hepatizon (Greek etymology: , English translation: "liver"), also known as black Corinthian bronze, was a highly valuable metal alloy in classical antiquity. It is thought to be an alloy of copper with the addition of a small proportion of gold and silver (perhaps as little as 8% of each), mixed and treated to produce a material with a dark purplish patina, similar to the colour of liver. It is referred to in various ancient texts, but few known examples of hepatizon exist today.

alloy of silver

alloy

alloys of the precious metals platinum and iridium

type of lead–acid battery