Chrysoberyl is a hard, tough, and durable gem. Although lacking the fire of other gemstones, chrysoberyl gems are very valuable. Most chrysoberyl is yellow, and some are brown or green. A rare, costly variety, known as alexandrite, exhibits different colors in natural and artificial light. If viewed in sunlight, its color is dark yellow-green to greenish-blue. If viewed in artificial light, its color is red. Alexandrite was discovered on the birthday of the Russian Czar Alexander II, and was named in his honor.

Another expensive form of chrysoberyl is the unusual cat's eye variety. When polished as cabochons, these stones exhibit a narrow band of concentrated light along the width of the gem. This effect, known as cat's eye effect, is caused by inclusions of fine, slender parallel mineral fibers in the gem. The cat's eye variety may be called "cat's eye", cat's eye, "precious cat's eye", "oriental cat's eye", "catseye", or "chrysoberyl cat's eye". Many other gems also exhibit a cat's eye effect, but only chrysoberyl's cat's eye enjoys the privilege of having the name "cat's eye". (All other gems that exhibit a cat's eye effect have the gem name preceding, such as "quartz cat's eye", whereas chrysoberyl's cat's eye is known simply as "cat's eye".)
In some chrysoberyl, the cat's eye effect is weak. It appears as a billowy, floating light reflection as opposed to a bright, concentrated band of light. Such chrysoberyl is known as cymophane, and the effect is called "cymophane effect".

USES
All colors of chrysoberyl are faceted as gems for jewelry. The most common color for jewelry is yellow, but brownish and greenish stones are also seen. Alexandrite is faceted with the brilliant and cushion cuts, to make the color change most recognizable. Cat's eye's are cut into cabochons.

r-changing variety of chrysoberyl
Cat's eye - variety of chrysoberyl exhibiting a narrow band of concentrated light across its polished surface
Cymophane - variety of chrysoberyl exhibiting a billowy, floating light reflection on its polished surface
Chrysolite - yellow, transparent variety of chrysoberyl

FALSE NAMES

Blue Alexandrite - Color changing sapphire (sapphire with the same optical phenomenon as alexandrite)

SIMILAR GEMSTONES
Topaz, heliodor, peridot, yellow sapphire, and zircon may resemble yellowish, brownish, or greenish chrysoberyl. The color-changing habit of alexandrite prevents it from being confused with any other gems. Chrysoberyl cat's eye can be distinguished from other cat's eye minerals by its greater hardness.

ALSO SEE

• The mineral Chrysoberyl
• The mineral Beryl
• Heliodor
• Golden Beryl

PICTURES

Special thanks to Gem Hut for most of our gem images. The gems displayed or others like them can be purchased through GemHut by clicking the link below each picture.

Picture: Light yellow Chrysoberyl
Size: 1.05 ct. (both gems)
Cut: Round
Collection: Gem Hut

Picture: Brown Chrysoberyl
Size: 1.49 ct.
Cut: Round Portugese
Collection: Gem Hut

Picture: Dark yellow-green Cat's Eye
Size: 1.01 ct.
Cut: Cabochon
Collection: Gem Hut

Picture: Pale yellow Cat's Eye
Size: .41 ct.
Cut: Cabochon
Collection: Gem Hut