Chrysoberyl should not be confused with beryl. It is a hard and durable gemstone and when it is well cut, the gems are brilliant but they lack fire. The word chrysoberyl is derived from the Greek words meaning golden and beryl.

An interesting aspect of its uncut crystals are the cyclic twin form which is called trillings. These twinned crystals look hexagonal in shape, but it is because of a triplet of twins with each "twin" taking up 120 degrees of the cyclic trilling.

Chrysoberyl also comes in chatoyant variety which means cat’s eye which is formed due to extremely minute tubelike cavities or needlelike inclusions of rutile present in an orientation parallel to the c-axis producing a cat’s eye effect which visible as a single ray of light passing across the crystal. This effect is best seen in gemstones cut in when it is cut en cabochon form perpendicular to the c-axis. It is only in the case of chrysoberyl that its cat’s eye is simply known as “cat’s eye” without any other designation unlike other stones having its name used as a prefix before the word “cat’s eye” like ruby cat’s eye, tourmaline cat’s eye, quartz cat’s eye etc.

Locations:

Chrysoberyl generally comes from Brazil, Sri Lanka and Russia. It also occurs in Burma, Zimbabwe, Tanzania and Madagascar. Cat’s eye is mainly found in Sri Lanka, Brazil and China.

Chemical Composition: Beryllium Aluminum Oxide
Crystal Structure: Orthorhombic
Hardness: 8.5
Specific Gravity: 3.70-3.72
Refractive Index: 1.744-1.755
Colors: Golden yellow, green-yellow and brown.
Luster: Vitreous

Astrological Relevance:

Chrysoberyl is considered as one of the birthstones for the zodiac sign of Leo (July 22 To August 22). Cat’s eye is considered as one of the birthstones for the zodiac sign of Gemini (May 21 To June 21).