Page 37 - Curriculum Visions Dynamic Book

 A gold nugget and flakes. Each flake is about 3 mm long.
 The largest piece of native gold ever found. Pieces of gold like this are called gold nuggets. This one, called Perseverance, was found in
the South African province of Natal on 16 December 1874. It weighed 3.3 kg and
was just over 12 cm long.
 Early 20th-century mining had become big business, rather than the province of many small-scale prospectors working by hand.
hydrothermal: a process in which hot water is involved. It is usually used in the context of rock formation because hot water and other fluids sent outwards from liquid magmas
are important carriers of metals and the minerals that form gemstones.
lode: a deposit in which a number of veins of a metal found close together.
vein: a mineral deposit different
from, and usually cutting across,
the surrounding rocks. Most mineral and metal-bearing veins are deposits filling fractures. The veins were filled by hot, mineral-rich waters rising upwards from liquid volcanic magma. They are important sources of many metals, such as silver and gold,
and also minerals such as gemstones. Veins are usually narrow, and were best suited to hand-mining. They
are less exploited in the modern machine age.
Gold rushes
Because people have put such
a high value on gold, its presence has attracted much attention throughout the ages. One of the main reasons for Spanish and Portuguese explorers taking an interest in South America was to plunder them as a source of gold.
The 19th century saw several major gold rushes in the United States, Canada, Russia, South Africa and Australia. The 1848–49 gold rush in California produced more new gold than had been found in the previous three centuries and made the United States the largest gold producer in the world. But as these gold fields were worked out, others took their place in Alaska, Australia (particularly Victoria) and South Africa (The Transvaal). Of the probable gold reserves, about half are to be found in the Witwatersrand area of South Africa.
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