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Greendale Diamonds Supply South Africa |
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Diamond Information Diamonds
Rough Diamonds
Princess Cut Diamond
Round Brilliant Cut Diamond
Fancy Coloured Diamonds are Very Rare & Expensive
Q: What is Diamond
A: Diamond is Carbon
It may seem surprising that diamond is simply carbon, just like charcoal
or graphite. In fact carbon has at least two other rare, and only
recently discovered forms, or allotropes, known as fullerenes.
The difference is caused by the different types of bonding between
adjacent atoms to form different types of crystalline structure.
In diamond, each carbon atom is bonded to four other carbon atoms in a
tetrahedral structure, like a pyramid. Each link or bond is the same
length, and the tetrahedral formation is therefore completely regular.
It is the strength and regularity of this bonding which makes diamond
very hard, non-volatile and resistant to chemical attack.
Theoretically a perfect diamond crystal could be composed of one giant
molecule of carbon.
Carbon is a non-metallic element with the atomic number of 6, and an
atomic Weight of 12. In combination with oxygen and hydrogen it is
contained by all living objects. In the form of graphite it appears
black or dark gray, opaque, and is very soft, whereas in the form of
diamond is it clear, colourless, and extremely hard. In fact diamond is
the hardest known naturally occurring substance.
Carbon has a density of about 2.3 and diamond about 3.5.
What Makes Diamond An Ideal Gemstone?
Diamond possesses many qualities which make it an ideal gemstone.
It is extremely hard, and also very tough and hard-wearing, and this
also helps it to take a very high polish. Some hard articles are brittle
which detracts from their durability. There are some things which are
harder than diamond.
In its pure form it is colourless, has a high refractive index, so has a
very high lustre.
It possesses high dispersion, meaning that different light wavelengths
are diffracted differently, giving a strong scintillating play of
prismatic colours.
Diamond Discoveries
Diamonds seem to have been known for about 3,000 years, being mentioned
in Exodus chapter 28, however in early times, other hard minerals were
often confused with diamond.
It is thought that the earliest diamonds were found in about the 12th
century B.C., in India , which remained the most important, if not the
sole, source until 1725, when diamonds were discovered in Brazil.
The Indian and Brazilian deposits had been almost exhausted when in
1866, the Eureka diamond was discovered in South Africa, followed by the
Star of South Africa in 1869. Shortly afterwards, the great South
African diamond rush had started, and South Africa remains one of the
world's most important sources of diamonds today.
Diamonds have since been discovered in many other regions of the world,
including Russia and Australia.
Until the South Africa finds, diamonds were so rare and valuable, that
they were only owned by the very wealthy. They were not available in
high street shops!
Why Are Diamonds So Popular?
Through the publicity and promotion given to diamonds largely by the De
Beers Company, and through the Diamond Promotion Service, diamonds have
become the most desired gemstone.
Thanks to large scale mining, and the development of efficient cutting
methods and equipment, diamonds have now become a consumer luxury
affordable to the masses.
Mass production jewellery manufacturing techniques have also helped to
bring diamond rings and other diamond jewellery into very affordable,
even commodity, price ranges.
Man Made
Another fact about diamond which surprises most people, is that more
diamond is now manufactured than mined. Synthetically produced diamonds
have been made since at least 1954, although the bulk of the synthetic
production is used for industrial purposes as diamond grit.
Gem quality synthetic diamonds have also been produced, although it is
still more expensive to manufacture them than to mine them.
Colour:
Pure diamond, if such a thing exists, is colourless.
Most diamonds are slightly coloured, even if the colouring is almost
imperceptible. The commonest colour is yellow which is caused by tiny
amounts of nitrogen being present in the crystal structure, others are
gray, light brown or greenish. Diamond can be almost any colour,
although strongly coloured attractive specimens are very rare, and as
such are not actively promoted by De Beers, probably in case consumers
realise that blue, red, green and other colours are attractive, and
start buying sapphires, rubies, emeralds and other gemstones instead of
diamonds!
As with many gemstones, colours can be artificially produced or
modified. Some fancy coloured diamonds are produced by irradiation and
subsequent heat treatment. Natural fancy coloured diamonds command very
high prices, especially the more more popular colours. Fancy coloured
diamonds where the colour has been artificially produced are no less
beautiful, but sell for more normal prices.
We occasionally have fancy coloured diamonds available in blue, green,
yellow, orange, pink, purple, brown, and even black.
Clarity
It is well known that most diamonds contain slight imperfections or
flaws, indeed I firmly believe that there is no such thing as a perfect
diamond. The higher the clarity grade of a diamond, the higher its
desirability, and therefore its price.
Cut, Proportion, and Shape
Most jewellers will tell you that "cut" is an important factor in the
price of a diamond. While this is true, most do not know clearly what
they mean by the word "cut". It can have several different meanings.
Firstly, it can describe the shape and facetting pattern of the diamond,
as in the modern round brilliant cut, the single or eight cut, pear
shape, emerald cut, square, baguette, oval, heart, triangle, princess,
marquise or fancy.
Secondly, it can mean the accuracy of the facetting, and the proportions
of the stone, and lastly it can apply to the polish or surface finish of
the stone.
Simulants
There have always been things which looked like diamonds, but were not
diamond. I have already stated that in early times other stones were
confused with diamond.
Any stone which looks like a diamond could be called a diamond simulant.
Natural or synthetic white sapphire, glass, colourless quartz (rock
crystal), rutile both natural and synthetic, yttrium aluminium garnet (YAG),
strontium titanite, cubic zirconia, and now moissanite, all simulate
diamond to a greater or lesser degree.
Do not confuse simulant with synthetic. A synthetic diamond is real
diamond, but not natural diamond. A simulant can be natural or
synthetic, but is not the same as the material it imitates.
The most abundant synthetic is cubic zirconia (CZ), which is a
remarkably good simulant. If it is set in a high quality realistic
mount, it is undetectable to the naked eye without instruments.
Moissanite is the latest synthetic simulant, and is very realistic
looking, and quite difficult to differentiate from diamond. |
History of South Africa Diamonds Diamonds and Platinum
South Africa's diamond mining industry dates back to 1867, when diamonds
were discovered near Kimberley, now in the Northern Cape. The Kimberley
diamond fields, and later discoveries in Gauteng, the Free State, and
along the Atlantic coast, emerged as major sources of gem-quality
diamonds, securing South Africa's position as the world's leading
producer in the mid-twentieth century. (Rough diamonds were produced in
larger quantities in Australia, Zaire, Botswana, and Russia.) Through
1991 most of Sout h Africa's diamonds were mined at only five locations,
but a sixth mine, Venetia--in the Northern Cape--opened in 1992 and was
expected to become a major diamond producer later in the decade.
The De Beers Consolidated Mines Company controlled most diamond mining
in South Africa and influenced international trade through a
diamond-producers' alliance, or cartel--the Central Selling
Organisation. The cartel enabled diamond producers to contr ol the
number of gems put on the market and thereby to maintain high prices for
gem-quality diamonds. The cartel was able to react to marketing efforts
outside its control by temporarily flooding the market, and thereby
driving down the price paid for an outsider's product.
Diamond prices fluctuated in the early 1980s, but the industry continued
to expand even in the face of international recession and the discovery
of the diamond-like cubic zirconia. Dollar prices for diamonds improved
in 1985 but dropped again in 1987, requiring De Beers to support the
market by withholding diamonds from dealers. Thus, annual production of
more than 10 million carats in 1985 and in 1986 dropped to 9.1 million
in the late 1980s. Gem and industrial diamond output in 1994 was 10.8
million carats, or roughly 11 percent of world production.
In 1990 the Soviet Union signed and openly acknowledged a contract to
sell its diamonds (estimated at a value of about R13 billion over a
five-year period) exclusively through De Beers. The action marked the
first time in nearly thirty years that the Soviet Union had openly
associated itself in commodity dealings with South Africa. Later that
year, De Beers announced a loan of R2.63 million to the Soviet Union,
against the security of an equivalent amount in diamonds.
Platinum group metals (platinum, palladium, ruthenium, rhodium, iridium,
and osmium), which occur together in ore seams and are mined in one
operation, were discovered in South Africa in 1924. Most of the
estimated 59,000 tons of reserves are in the B ushveld complex of
minerals; some concentrations are also found in the Transvaal and the
Witwatersrand complexes. Platinum is used in automobile catalytic
converters to reduce fuel emissions, as a catalyst in industrial
processes, and in making jewelry.
South Africa is the world's leading producer of platinum. Its output of
about ninety tons in 1993 accounted for almost 49 percent of world
production. South Africa's platinum mines have profited, in particular,
from the sale of rhodium, which sold for almost US$6,000 an ounce in the
early 1990s, but world market prices fell after that.
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Contact Us Email:
greendiam@tiscali.co.za
 
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Diamond Info |
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have always been things which looked like diamonds, but were not
diamond. I have already stated that in early times other stones
were confused with diamond. |
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