gold
For those who are interested, just a bit of info on gold,
the name GAUTENG is the Sotho word for gold.
Whilst in Gauteng I wanted to go down a gold mine but Wendy
asked me not to.
Pure gold is the most malleable and ductile of all the metals. It
can easily be beaten or hammered to a thickness of 0.000013
cm (0.000005 in), and 29 g (1.02 oz) could be drawn into a wire
100 km (62 mi) long. It is one of the softest metals (hardness,
2.5 to 3) and is a good conductor of heat and electricity. Gold is
bright yellow and has a high luster. Finely divided gold, like other
metallic powders, is black
Gold is extremely inactive. It is unaffected by air, heat, moisture,
and most solvents. It will, however, dissolve in mixtures
containing chlorides, bromides, or some iodides. It will also
dissolve in many oxidizing mixtures, in alkali cyanides, and in
aqua regia, a mixture of hydrochloric and nitric acids. The
chlorides and cyanides are important compounds of gold. Gold
melts at about 1064° C (about 1947° F), boils at about 5086° C
(about 2808° F), and has a specific gravity of 19.3; its atomic
weight is 196.967.
Gold also occurs in seawater to the extent of 5 to 250 parts by
weight to 100 million parts of water. Although the quantity of gold
present in seawater is more than 9 billion metric tons, the cost of
recovering the gold would be far greater than the value of the gold
that could thus be recovered.
Because of its relative rarity, gold became used as currency and
as a basis for international monetary transactions (see Dollar
(Gold Standard). The unit used in weighing gold is the troy
ounce; 1 troy ounce is equivalent to 31.1 grams.
The gold content in alloys is expressed in carats (24 carat = pure
100% gold). Coinage gold is composed of 90 parts gold to 10
parts silver. Green gold used in jewelry contains copper and
silver; white gold contains zinc and nickel, or platinum metals.
Gold is also used in the form of gold leaf in the arts of gilding and
lettering. Purple of Cassius, a precipitate of finely divided gold
and stannic hydroxide formed by the interaction of auric chloride
and stannous chloride, is used in coloring ruby glass. Chlorauric
acid is used in photography for toning silver images. Potassium
gold cyanide is used in electrogilding. Gold is also used in
dentistry. Radioisotopes of gold are used in biological research
and in the treatment of cancer (see Isotopic Tracer).
Gold-bearing rock with as little as 1 part of gold to 300,000 parts
of worthless material can be worked at a profit.
South Africa is the world’s leading supplier of gold, producing
about 600 metric tons annually; its most important gold mines
are in the Gauteng region. Some 70 other countries produce gold
in commercial quantities, but about 80 percent of the total
worldwide production now comes from South Africa, the United
States, the former Soviet republics, Australia, Canada, China,
and Brazil.
In 1991, the value of the gold produced in the United States was
about $3.4 billion. U.S. consumption, by major markets, included
jewelry and arts, 66 percent; industry, mainly
Johannesburg, city in northeastern South Africa, in Gauteng
Province. When the city was founded in 1886, only remnants of
ancient iron furnaces and a few isolated farms were in the area, a
part of the Witwatersrand region. Beneath these open spaces
were found the world’s largest known gold deposits, bringing total
transformation to the richest spot on earth, as a British
government minister of the time called it. In the early 1990s
Johannesburg was at the center of one of the largest urban
complexes in sub-Saharan Africa, a cluster of cities stretching
from Pretoria south to Vereeniging and from Springs west to
Krugersdorp.
It’s not hard to meet expenses…they’re everywhere.
Marius Calitz
mariusc@…