A
naturally occurring, dense, lustrous, yellow precious metal widespread
in low concentrations in all igneous rocks. Its abundance in the Earth's
crust is estimated at about 0.005 parts per million.
Four
countries, South Africa, Russia, the United States, and Australia, account
for two-thirds of the gold produced annually throughout the world, (South
Africa, with its vast Witwatersrand mines, produces about one-third
of the world's gold) with Canada and Brazil also having substantial
deposits.
There
are numerous methods of recovery depending on the type of deposit.
As
a food additive it is used solely for external decoration where it can
be found on chocolate confectionery, in the covering of dragées
and the decoration of sugar-coated flour confectionery.
Chemically,
gold is very inactive and therefore virtually harmless, however as there
is no dietary requirement it is probably best avoided.
Not
permitted in Australia.