ZIRCON, DIAMOND,
AND
SYNTHETIC
CUBIC ZIRCONIA
The gemstone that comes closest
to imitating a diamond's
appearance is colorless zircon.
Among man-made stones, the
most similar to diamond is
synthetic cubic zirconia.
Though cubic zirconia occurs
in nature, it does not occur
in size large enough to cut
as gemstones. Zircon is no
longer the diamond imitation
of choice, but since the
18th century it has drawn
attention for having a brilliance
similar to diamond's. Comparing
the similarities between
zircon, we arrive at the
chart shown below. |
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Colorless Zircon
as a
Diamond Imitation
Brilliance is maximized by an optimum
cut that is based on a consideration
of the crystal's properties such
as transparency, refractive index,
and hardness. Dispersion is the
phenomenon of light being split
into its component colors of red,
orange, yellow, green, blue, and
violet, as when it travels through
a prism. Both zircon and diamond
have characteristically strong
dispersion.
The photograph shows how zircon
has a lower level of transparency
and a weaker brilliance than diamond,
but under a penlight zircon displays
dispersion that is almost equal
to that of diamond. The transparency
and brilliance of diamond are truly
outstanding, its minute mosaic
pattern scintillating with flashes
of rainbow-colored dispersion as
it is moved. |
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Synthetic Cubic Zirconia
as a Diamond Imitation
Synthetic cubic zirconia shines
brightly and has abundant dispersion,
but its individual facets lack
sharpness. The difference between
diamond's hardness of 10 and cubic
zirconia's 81/2, and the greater degree
of care taken while polishing diamond,
become apparent in each facet.
In addition, if a loose diamond
and synthetic CZ of about the same
size are placed in the palm of
the hand, the difference in their
weights will be noticeable enough
to make separation possible.
Compared to zircon, synthetic cubic
zirconia's beauty is much closer
to diamond, but it lacks value.
Synthetic cubic zirconia are sometimes
set in 22-karat gold jewelry in
the Middle East, and it is important
not to mistake them for diamonds
when making a purchase. |
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