18 articles
Au
Au is the chemical symbol for gold, from the Latin aurum, a soft yellow metallic element with atomic number 79 that occurs natively and resists nearly all acids.
Bullion
Bullion is precious metal, most commonly gold, silver, platinum, or palladium, authenticated to a specified fineness and valued at the market price of its metal content, in bars and coins.
Colored gold
Colored gold is gold given a color other than its natural yellow, achieved by alloying, forming intermetallic compounds like purple AuAl2 and blue AuIn2, or surface treatments that produce black, brown, and blue finishes.
Cupronickel
Cupronickel, also written copper-nickel or white copper, is an alloy of copper and nickel, copper dominant, best known for coinage and for seawater equipment such as ship condensers and heat exchangers.
Electrum
Electrum, also called green-gold, is a naturally occurring gold-silver alloy whose color ranges from pale yellow to white, used for the first coins struck in Lydia around 650 BCE.
Fineness
Fineness is the content of a precious metal in an alloy, expressed in parts per thousand by mass, the standard measure for gold, silver, platinum, and palladium purity.
Gold
Gold, a chemical element with symbol Au and atomic number 79, is a dense, soft yellow metal prized since prehistoric times as jewelry, coinage, and a store of value.
Gold bar
A gold bar, also known as a gold ingot, is refined gold cast or minted into a standardized shape, from 1-gram retail bars to 400-ounce wholesale bars.
Gold extraction
Gold extraction, also called gold processing, is the set of mining, concentration, and chemical processes used to recover gold from ore, dominated by cyanide leaching in industry and mercury amalgamation in artisanal mining.
Gold nugget
A gold nugget is a naturally occurring mass of native gold, ranging from a few grams to tens of kilograms, found in veins or concentrated in placer deposits.
Hallmark
A hallmark is an official mark certifying that an item of gold, silver, platinum, or palladium has been tested and meets legal standards of purity.
Noble metal
A noble metal is a metallic element highly resistant to corrosion and oxidation, such as gold, silver, and platinum, usually found in nature in its raw form.
Orichalcum
Orichalcum, Greek oreichalkos, is the classical name for a copper-zinc alloy like brass. In Roman times it was the metal of sestertius and dupondius coins, and Plato linked it to Atlantis.
Precious metal
A precious metal is a rare, naturally occurring metallic element of high economic value, resistant to corrosion; the class is usually taken to include gold, silver, and the six platinum-group metals.
Silver
Silver (symbol Ag, from the Latin argentum) is a soft, lustrous white metallic element with atomic number 47, prized since prehistoric times for coinage, jewelry, and tableware.
Silver as an investment
Silver as an investment is the purchase of silver or silver-linked financial instruments to preserve or increase wealth, through bullion, trusts, futures, or mining shares.
Sterling silver
Sterling silver is a silver alloy containing 92.5% pure silver, with copper usually making up the rest, and has been the standard for silverware since the 14th century.
Tanaka Kikinzoku Kogyo
Tanaka Kikinzoku Kogyo (田中貴金属工業) is a Japanese precious metals company founded as a Tokyo bullion dealer in 1885, refining and recycling gold, silver, and platinum group metals.