REGARDING "SYNTHETIC" CUBIC
ZIRCONIA
In 1965, the textbooks of the Gemological
Institute of America (GIA) did not
make any mention of synthetic cubic
zirconia. At the time, the man-made
diamond look-alikes were synthetic
spinel, synthetic sapphire, strontium
titanate, and synthetic rutile. All
of these can be color-less, but they
lack attractive brilliance and look
different from diamond. The era of
synthetic cubic zirconia came into
full swing around the mid-1970s,
and the cost of one carat of rough
material has dropped from about $10
at the time to the current level
of a few pennies, just hundredths
of its former price. This is a prime
example of why man-made stones cannot
be called "gemstones." Though
attractive, they have no rarity because
they can be produced in massive quantities.
Cubic zirconia appears as extremely
tiny crystals in nature, and none
are large enough to cut as gemstones. |
JUDGEING QUALITY
Blue zircon's transparency drops
when its tone gets too dark, causing
it to lose its beauty. A beautiful
stone should not be too dark. There
also should be no eye-visible imperfections,
and the cut should be carefully
executed, with no abrasions or
tiny scratches along the facet
junctions.
Blue zircon is heated to bring out
its blue color. There is a degree
of risk that comes with treatment,
such as the possibility of fractures
developing during the process or
the desired color not being achieved.
The price of a beautiful blue zircon
reflects a combination of the beauty
of the stone and the risks associated
with treatment. |
HOW
TO CHOOSE
The ideal choice for
a cat's-eye chrysoberyl is one
that exhibits distinct chatoyancy
and a well-balanced change in
its honey-colored and milky
portions as it moves, and has
a good overall shape and form.
In reality, however, such a
stone rarely exists. The optimum
size for a cat's-eye used as
the main stone in a ring is
7 to 8 millimeters (about .25
to .33 inch), and a weight of
over two carats. Assuming that
a pleasing overall appearance
is the absolute minimum requirement,
it is realistic to choose a
stone with emphasis on either
the appearance of the chatoyancy,
or the stone's color. When buying
loose stones, it is especially
important to not select a stone
with a base that is too deep.
It is difficult to set a deep
stone in jewelry, and odds are
that such a gemstone would end
up not being used at all. The
value of a three-carat-size
cat's-eye chrysoberyl of jewelry
quality is approximately US
$5,000 for the stone alone.
(2001) |
| A
GEM OF VALUE |
 |
Weight:3.20ct
Size(mm):Diameter 8.18.2
x D5.76
Heated
Gem Quality
US $1,000 |
|
|
