Description
A soft, inert, shiny yellow metallic element that is beautiful and easy to work. Gold has been highly valued and used for artifacts since before 5000 BCE. Alluvial deposits were used in Iran, Turkey, Egypt, Greece, India, and China. In medieval Europe, most gold was obtained from Saxony and Austria. Major gold deposits have been found in South Africa, Columbia, Australia, Russia, Canada (Yukon) and the U.S.(California). Native gold, found in quartz veins (vein gold) and alluvial deposits (placer gold), generally contains some silver and copper. Gold is purified by dissolution in mercury or cyanide solutions, by melting, or by electrodeposition. The purity of commercial gold is expressed in karats which is the number of parts of gold in 24 parts of the alloy. Gold is extremely malleable and can be pressed into a continuous film of 0.1 micrometer thickness. Gold is primarily used for monetary systems and for jewelry. Other uses for gold include conductor in electrical devices, dentistry, as a pigment in paints and ceramics and for gilded decoration.
See also white gold, yellow gold, and green gold.
Synonyms and Related Terms
Au; aurum (Lat.); Goud (Ned.); or (Fr.); Gold (Deut.); oro (It., Esp.); ouro (Port.); guld (Sven.); burnish gold
| Au (atomic no. 79) |
| 7440-57-5 |
| 2.5 - 3.0 |
| 1064.76 |
| atomic wt = 196.9665 |
| 19.3 |
| 2700 |
Other Properties
Inert. Not attacked by acids, air, or oxygen. Soluble in aqua regia, alkali cyanides, thiocyanates, or mercury.
Isometric crystal system occuring as octahedral or cubic forms; often distorted. Luster = metallic. Streak = goldish-yellow. Ductile and malleable.
Hazards and Safety
May be tarnished by sulfur. No significant health hazards.
Fisher Scientific: MSDS
Additional Information
° O. Untracht, Metal Techniques for Craftsmen, Doubleday and Co., Garden City, NY, 1968.
° Mineralogy Database: Gold
° Web Elements: Website
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Last updated on: 6/26/2009 2:11:59 PM
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