ARTICLE
ON GOLD
by Catherine Saliba
BELOVED TREASURES
AUSTRALIA.
I enjoyed my Chemistry classes in High School immensely.
Gold is one of the
heaviest substances on earth and when pure, it has a specific
gravity of 19.3.
The international weight measurement
of Gold is - One troy ounce which equals 31.1 grams.
Its Atomic Number is 79; chemical
element on the Periodic Table is the Symbol Au (aurum
in Latin, meaning glow of sunrise).
Pure gold is a beautiful rich yellow metal worshipped and
highly prized by many societies throughout human history.
Gold is the most malleable metals and can be easily moulded & shaped because pure Gold easily bends and is also one of the most non reactive metals on Earth.
Gold jewellery is always mixed with other
metals to increase its resistance and strength. The ‘alloy’ (mixture of 2 or
more metals) is identifiable by its carat which is determined by the percentage
of Gold in the alloy.
The scale is 1 to 24 (24 carat is Pure Gold)
and the most common carat weight in Australia is 9ct Gold (375 – 37.5% gold
content), 14ct Gold (hallmarked 585 = 58.5% gold content), 18ct Gold (hallmarked
750 = 75% gold content), 22ct Gold (hallmarked 916 = 91.6% gold content), 24ct Gold (hallmarked 999 = 99.9% gold content).
Pure 24ct Gold is never used in jewellery
because it is easily bent out of shape and does not have much resistance to
pressure. Gold does not tarnish, is a high conductor of electricity, has a high resistance
to corrosion & chemical reactions, and is unaffected by most
chemicals, however it can discolour by exposure to bleach, chlorine & certain
detergents.
http://www.belovedtreasures.com.au/products.asp?cat=59
YELLOW GOLD - GOLD that
retains its original golden yellow colour even though it is mixed (alloyed) with other metals to strengthen its resistance & toughness.
ROSE GOLD - GOLD with a pink / reddish tone, the colour
is created by the mix (alloyed) of the Gold with copper.
WHITE GOLD - GOLD that is pale and almost
silver-coloured, the colour is created
by the mix (alloyed) of the Gold with nickel, zinc, and
sometimes palladium.
Gold masks, amulets, figurines & ornaments were used by many Ancient Civilisations and GOLD has made a monetary standard in the World economy possible.
The concept of money opened up the World's economies to expand and
prosper. During the Classic period of Greek and Roman rule in the western
world, gold and silver both flowed to India for spices and to China for silk.
At the height of the Empire (A.D. 98-160), Roman gold and silver coins reigned
from Britain to North Africa and Egypt.
Money had been invented. Its name was GOLD.
Interesting
Info:
- Most of the Earth's Gold lies at its core - it sunk
there in the Earth's infancy due to the high density of the metal. Virtually all
of the gold that mankind has discovered is considered to have been deposited
later by meteorites which contained the element, with the asteroid that
formed the Vredefort Crater in South Africa estimated to have been one of the largest ever to strike
Earth (at least since the Hadean eon
some four billion years ago) and thought to have been approximately 300km
across in diameter; this crater has been implicated
in the formation of the largest gold mining region on earth – Witwatersrand Basin It holds the world's largest known Gold reserves
and has produced over 1.5 billion ounces (over 40,000 metric tons).
- Astronaut visors contain 24 carat pure gold;
the Gold is transparent enough for astronauts to see through and protect them
from the harmful solar rays because gold prevents overheating by reflecting
away infra-red radiation.
- Gold is so rare that only approximately 152,000
metric tons has been mined in all recorded history. To put it in perspective,
you can fit all of the world's known gold into less than 100 tractor trailers.The
majority of gold (between 70% - 80%) is privately owned in the form of jewellery
and 10% to 20% of gold is stored in banks. The remaining gold is used in other industries, such as dentistry and
technology.
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| Gold in various forms. |
