Formula:
Au
As a Commodity:
Gold
Colour:
Rich yellow, paling to whitish-yellow with increasing silver; blue & green in transmitted light (only thinnest folia [gold leaf])
Lustre:
Metallic
Hardness:
2½ - 3
Specific Gravity:
15 - 19.3
Crystal System:
Isometric
Member of:
Copper Group
Gold is one of the first minerals used by prehistoric cultures. The Latin name for this mineral was "aurum" and Jöns Jakob Berzelius used Au to represent the element when he established the current system of chemical symbols. The Old English word "gold" first appeared in written form about 725 and may further have been derived from "gehl" or "jehl". May be derived from Anglo-Saxon "gold" = yellow. (Known to alchemists as Sol.)
Copper Group. Gold-Silver Series and Gold-Palladium Series.
A native element and precious metal, gold has long been prized for its beauty, resistance to chemical attack and workability. As it is found as a native element, has a relatively low melting point (1063 degrees Celsius) and is malleable, it has been used by mankind for thousands of years.
Gold is used as a standard for international currency and is also widely used in jewelry, electronics (where its superb properties as a conductor help offset its tremendous cost), dentistry and in photographic processes.
Gold occurs in significant amounts in three main types of deposits: hydrothermal quartz veins and related deposits in metamorphic and igneous rocks; in volcanic-exhalative sulphide deposits; and in consolidated to unconsolidated placer deposits. It may also occur in contact metamorphic or hypothermal deposits (eg. Skarns), or epithermal deposits such as volcanic fumaroles. It is most commonly found as disseminated grains in quartz veins with pyrite and other sulphides, or as rounded grains, flakes or nuggets in placer deposits in recent to ancient stream and river deposits. Gold is often panned from such deposits by taking advantage of its high density to wash away the lighter sediments from a pan or sluice.
Nuggets are almost exclusively hypogene in origin, forming mostly in veins, but can be somewhat modified in form and chemistry by weathering, erosion, and transport (Hough et al., 2007).
A native element and precious metal, gold has long been prized for its beauty, resistance to chemical attack and workability. As it is found as a native element, has a relatively low melting point (1063 degrees Celsius) and is malleable, it has been used by mankind for thousands of years.
Gold is used as a standard for international currency and is also widely used in jewelry, electronics (where its superb properties as a conductor help offset its tremendous cost), dentistry and in photographic processes.
Gold occurs in significant amounts in three main types of deposits: hydrothermal quartz veins and related deposits in metamorphic and igneous rocks; in volcanic-exhalative sulphide deposits; and in consolidated to unconsolidated placer deposits. It may also occur in contact metamorphic or hypothermal deposits (eg. Skarns), or epithermal deposits such as volcanic fumaroles. It is most commonly found as disseminated grains in quartz veins with pyrite and other sulphides, or as rounded grains, flakes or nuggets in placer deposits in recent to ancient stream and river deposits. Gold is often panned from such deposits by taking advantage of its high density to wash away the lighter sediments from a pan or sluice.
Nuggets are almost exclusively hypogene in origin, forming mostly in veins, but can be somewhat modified in form and chemistry by weathering, erosion, and transport (Hough et al., 2007).
