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Amongst the alloys made of gold, silver, and copper, the hardest is the 18.1 K pink gold (75.7% gold and 24.3% copper). An alloy with only gold and silver is the hardest at 15.5 K (64.5% gold and 35.5% silver). During ancient times, due to impurities in the smelting process, gold frequently turned a reddish color.
Electrum is a naturally occurring alloy of gold and silver, [1][2] with trace amounts of copper and other metals. Its color ranges from pale to bright yellow, depending on the proportions of gold and silver. It has been produced artificially and is also known as "green gold". [3]
Corinthian bronze (gold, silver) Cunife (nickel, iron) Cupronickel (nickel) CuSil (silver) Cymbal alloys (tin) Devarda's alloy (aluminium, zinc) Hepatizon (gold, silver) Manganin (manganese, nickel) Melchior (nickel); high corrosion resistance, used in marine applications in condenser tubes.
Black Hills gold jewelry is a type of jewelry manufactured in the Black Hills of South Dakota. It was first created in the 1870s during the Black Hills Gold Rush by a French goldsmith named Henri LeBeau, who is said to have dreamed about the design after passing out from thirst and starvation. Black Hills gold jewelry depicts leaves, grape ...
To avoid the irritation of damaged jewelry from such scratches and flaws, gold colored titanium jewelry is a safer substitute. Piercing jewelry is often made of a gold alloy , the most common being 18k, with 24k being entirely pure and much softer. 18k gold usually contains 75% gold and the remaining 25% copper , silver and traces of other metals.
Orichalcum or aurichalcum / ˌ ɔːr ɪ ˈ k æ l k ə m / 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 ...
Tumbaga is an alloy composed mostly of gold and copper. It has a significantly lower melting point than gold or copper alone [citation needed]. It is harder than copper, but maintains malleability after being pounded. Tumbaga can be treated with a carboxylic acid, such as oxalic acid, to dissolve copper off the surface. What remains is a shiny ...
Nordic Gold, composed of 89% copper, 5% aluminium, 5% zinc, and 1% tin, is a more recently developed aluminium-bronze alloy for coinage. It was first used for the Swedish 10-kronor coin in 1991, and became widespread after the introduction of Nordic gold 10, 20 and 50-cent Euro coins in 2002.