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Volume 52

One of the most interesting, yet least known, of the important gemstones, Chrysoberyl deserves a special recognition for its rarity and astounding beauty. The rare presence of chrome traces turns Chrysoberyl into Alexandrite. The stone was named after Czar Alexander II of Russia. Alexandrite changes color from soft green in sunlight to deep red in candle or artificial light. The composition is the same as Beryl, but the distinct pleochroism shows deep red, orange-yellow and green colors. Because of the chromium in Alexandrite it may fluoresce a dull red in short-wave and long wave UV.

SOURCES: Russia has long been the most desirable source for gem Alexandrite. The finest comes from the Takowaja emerald mines in the Ural mountains. This is where it was discovered in 1830.

Brazil: Alexandrite from Brazil is mined in the States of Minas Gerais and Bahia. Until the discovery of its new Alexandrite vein, Brazil commanded little or no respect as an Alexandrite producer. At present all major Brazilian mines are under government control. Recent finds have led to a great deal of infighting between mine owners. The

"wars" became so violent that the government trenched a moat around and posted soldiers upon, the only remaining operating mine. For prized stones, the trade counts on Sri Lanka, but only on a sporadic basis. These stones always seem to have an undertone of brown or yellow. Seldom do you see the fine 100% color change exhibited in the new Brazil or old Russian material. Sri Lankan material can often exceed 20 cts in size and be extremely clean. But the faint orange color change usually can only be seen in laboratory conditions. Nobody knows how much material from the new Brazilian find has been cut. But insiders estimates range from 5,000 to 10,000 carats. These stones boast admirable color purity and richness. The completeness of the color change in most of the material is one of the most amazing things about the new find.

Nigeria: This new source of Alexandrite is yielding beautiful Blue Green material with much better clarity than the Brazilian material. However, the color change is more to an orangish pink color rather than rose or red.

CLARITY: Alexandrite is a TYPE III gemstone as classified by the Gem Institute of America. That means you can expect Alexandrite to have numerous and eye visible inclusions. The stone pictured about would be considered very clean even though you can easily see the inclusions with your naked eye.

PRICE & SIZE: As of May 2005, fine quality, nearly eye clean, 2-to-3 carat Brazilian stones were already commanding prices of $20,000 to $35,000 per carat. Although 30 to 40 carat Russian Alexandrites are known to exist, most are around 8 carat and you rarely see Siberian stones that have the right color and purity. These stones can fetch upwards of $50,000 per carat. One should not forget that the primary buyers of Alexandrite for some time now have been the Japanese. Especially fond of sizes between 2 and 4 carats, they have so far swallowed prices exceeding $25,000 per carat. Click here for our current price guide. prices

CUT: The nature of the Alexandrite crystal and its unique trichoric phenomenon dictates the rough will be cut for purity, color change, and size. Stones are not cut to "calibrated" size, nor seldom is the rough wasted to cut stones over 5 mm round. Pearshape, princess, trillions, emerald-cut, or marquette shapes likewise are not the shape of choice to which Alexandrite is fashioned. Rather the antique or cushion shape, small rounds under 3 mm or elongated ovals dominate the finished supply.

Hardness: 8.5 Toughness: Excellent RI: 1.746-1.755 DR SG: 3.73 Group: Chrysoberyl Sources: USSR, Brazil, Sri Lanka Color: Daylight- bluish green Incandescent - Purple-Red Enhancements: None known

Fluorescence

Incandescent or Torch

CATSEYE: Cat's eyes and stars in all gem varieties have long been coveted for their beautiful and mysterious

optical effects. Glance at a cat's eye alexandrite and you will see a band of light silently gliding across the surface. Sometimes a fainter second arm of light will intersect the bright band, creating a color changing star alexandrite. Cat’s eye has the longest history of any of the chrysoberyl varieties. It was known in Rome by the end of the first century, but even before, had been treasured (and continues to be, to this day) in the Orient.

According to Hindu belief, cat’s eye preserved an owner’s health and guarded him or her against poverty. Natives of Sri Lanka believed that it protected the wearer from evil spirits.

The gem was virtually forgotten in the West until the late 19th Century, when the Duke of Connaught gave a cat’s eye betrothal ring to Princess Louise Margaret of Prussia. The gems popularity and price rose instantly and Sri Lanka (then Ceylon) had difficulty keeping up with the demand.

Alexandrite Catseye is one of the rarest and costliest of gems. Catseye is the most valuable chatoyant gemstone. The eye should also “open” widely in oblique illumination, and close sharply in direct illumination. If the light is just right, the daylight color will appear on one side, the eye in the center, and the color change on the other. Such stones are true rarities.