Diamonds, best of all gems

Diamonds, best of all gems

Fabian H. Chandra, Gemologist, Jakarta

Answering the seemingly simple question, 'What kind of gems
are found in Indonesia?', is actually quite difficult. There are
lots of them but the most important are diamonds, pearls, opals,
quartzes and chalcedonies.

Still, the best and most expensive is the diamond,
particularly the pink diamond. This is similar to the sort found
in the Argyle diamond mines in Australia's Northern Territory.

There are two diamond producers in Indonesia -- Martapura in
South Kalimantan and Ngabang in North Kalimantan.

Diamonds mined in Kalimantan have relatively good clarity as
they are rounded, river-tumbled stones. Therefore most of them
will end up in pieces of jewelry. These diamonds are alluvial,
meaning they are carried long distances by the flow of the river
from its source.

Around 95 percent of Australian diamonds are of industrial
quality and are not suitable for use as gems. They are normally
used as industrial abrasives, in diamond drilling equipment, or
in glass cutting knives.

Compared to giant producers like South Africa (with its
Kimberley mine), Australia and Namibia, Indonesia is considered a
very small producer. But being the 12th largest in the world --
perhaps now only 14th due to the discovery of diamond deposits in
North America -- Indonesia is still a significant player.

The biggest diamond ever found in Indonesia is the Trisakti
diamond, weighing in at 166.72 carats. It was found in 1965 in
the Cempaka district of South Kalimantan before being cut in
Amsterdam. However, its whereabouts remain a mystery even today.

Among the world's most famous diamonds are the Cullinan I or
Star of Africa, which weighs 530.20 carats and is now kept in the
Tower of London; the Tiffany (128.51 carats), the Koh-i-Noor
(108.92 carats) and the Florentine (137.27 carats).

The price of a diamond depends on the four C's - color,
clarity, cut and carat weight.

Colors range from the expensive, very fine white to the less
valuable light yellow and light brown. Natural highly saturated
yellow diamonds, known as canary yellow, are more expensive than
colorless ones. Some of the other fancy colors that can be found
are blue, purple, pink, red, orange and green. Almost every color
of the rainbow is represented.

The meaning of the term "clarity" varies throughout the world.
In Germany, clarity means inner perfection but in the United
States and Scandinavia, clarity also takes into account aspects
of the quality of the outer finish.

The third factor is the diamond's cut. Good cutting enhances a
diamond's beauty. It produces effects known as 'brilliance' and
'scintillation'. Brilliance is the total white light reflected to
the eye from inside the stone and its surface. Scintillation is
the dynamic pattern of sparkling reflections. Most diamonds are
cut in a round brilliant cut. Another popular cut is known as the
fancy cut. Lately, the square princess cut has gained wider
acceptance as an alternative to the brilliant variety.

Carat weight is related to size. One carat equals one fifth of
a gram or 0.2 grams. The price of larger diamonds is higher as
they are harder to find in nature. Sometimes the price of a carat
diamond of certain quality is US$1,000 per carat.

Imagine the price of the Cullinan I (530.20 carats), which is
in a pear shape, if the price of one carat of a medium quality
pear shape can reach up to US$5,000 retail.

The Cullinan I is the most expensive diamond for its size. But
the most expensive diamond in terms of carat weight is
surprisingly small.

At the end of the 1980s, Christie's in New York auctioned a
natural red diamond that weighed just 0.87 carats. The offers
rose rapidly, with the price eventually reaching $1 million per
carat or $870,000 for the tiny diamond. It is the most expensive
gem on earth in terms of per carat weight.

As Marilyn Monroe said in one of her movies Diamonds are a
girl's best friend - she might have one day referred to this
diamond if she had lived longer.