Cats eye chrysoberyl with its band of reflected light across the middle ,has always reminded observers of the eye of the cat
The band of light that an observer sees in the middle of the stone is the CAT’S EYE EFFECT. The stone in itself is not cat’s eye.
In Navratan
Lahsuniya is CAT’S EYE CHRYSOBERYL NOT ANY OTHE CAT’S EYE EFFECT STONE.
Cat’s eye effects occur in other gemstones. LIKE CAT’S EYE QUARTZ, CAT’S EYE SILLAMINTE.
Cat’s eye effect is gemologically called Chatoyancy that is a result of tiny fibers, or needles, naturally arranged in a parallel configuration.
Cat’s eye chrysoberyl ranges from brown to greenish yellow. The finest quality specimens boast a golden color with bands that span the entire length of the gem. The bands themselves are distinct, silvery-white and straight.
CAT’S EYE CHRYSOBERYL show another feature called MILK AND HONEY. With the light perpendicular to the chatoyant band, the side close to the stone shows stone’s original body color while the other side shows a milky appearance.
Chemical composition
Beryllium aluminum oxide.
Species Chrysoberyl
Refractive Index 1.746-1.755(+0.004/-0.006)
Specific gravity 3.73(+/-0.02)
Melting point 1870 C (Approx)
Source
India
Sri Lanka
Brazil
East Africa
Hardness & Toughness
Hardness(resistance to scratching) 8.5 on the Mohs scale
Toughness(resistance to breaking and chipping) Excellent to good
Stability (Resistance to Heat and Chemicals)
Heat Stable
Chemicals None
Care and Cleaning
Ultrasonic cleaning Usually safe
Steam cleaning Usually safe
Warm soapy water Safe
Imitations
Cat's eye Glass
When buying Cat's eye be aware of:
It is important that the 'eye' has a fine line running right through it, and that it can be recognized clearly
Fine cat's eyes should be of a distinctive colour and be as transparent as possible.
The most popular ones are those of a beautiful honey yellow and those with fine green tones.
Please see the
Checklist on how to buy gemstones scientifically