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From the "Congo Cube"
to
the Diamond Bead
Until a few years ago is was totally impossible to cut
perfectly spherical diamonds. Since a diamond has different degrees of
hardness in the different directions of its crystalline lattice (and
therefore only a diamond will cut another diamond), you usually get
irregular elliptical forms. In 1989 a diamond cutter from Antwerp took
out a patent for a procedure for “rubbing” gems. It was the first time
that the diamond’s anisotropy of hardness could be outwitted, but almost
half of the raw diamond’s material got lost, and the cutting procedure
left marks on the surface.
In 1998 the Viennese diamond dealer Ervin Knoepfler met a
Spanish engineer who had been working on converting industrial diamonds
into looming diamond spheres for a long time. It is made possible by
state-of-the-art laser technology that is also used in medicine: with
pulsating, spatially well-defined laser flashes you can also cut, round
out and drill diamonds.
Original material are cubic hazy diamond monocrystals from
the Congo (and not polycrystalline diamond aggregates – borts – or
diamondites, as is sometimes assumed). The “Congo Cubes” are tumbled,
sorted, cut round with a laser beam, rubbed and given a mirror polish.
You can even cut tiny circular or hexagonal facets onto the surface and
so produce a silky-mat sheen. Raw cubes from the Congo usually have a
maximum weight of 200 ct (40 g), and can be turned into Diapearls of 70
to 80 ct. The biggest sphere that has been produced until today weighs
40 ct, or exactly 8 g. According to the range of colours of the raw
material from the Congo (see Extra Lapis No. 18: “Diamant”, pp. 21-22)
the spheres’ colouring varies from milk white, resin yellow, and orange
to olive green and brown.
Since the production process from the cube to the
fine-polished and drilled sphere takes four weeks, irrespective of the
bead’s size, the production of Diapearls of less than 3 ct (0.6 g) is
uneconomic. The Diapearl’s price per carat is about US$ 500. It is true
that the price is very low for a diamond (an eye-clean white diamond of
one carat costs at least 30 times more), but what impresses is its size.
The most expensive Power Bracelet until today, which consists of 21
Diapearls and as a whole weighs 139.44 carat, was exhibited at the
Diamond Show of the Munich Mineral Show in October. But that is not all
yet. Rumour has it that pop star Michael Jackson is considering ordering
a Power Bracelet – for three million dollars …
Stefan Weiß
From:
LAPIS "Aktuell", December 2000
(Journal: Lapis Mineralien Magazin, vol. 25:12, p. 5, published
by Christian Weise Verlag, Munich).
Yours faithfully,
Ervin Knoepfler
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