FELDSPAR CATS EYE 6.87 Cts NATURAL SRI LANKA LOOSE GEMSTONE 21373

100% Natural – Not treated in any way.
Rare Collectors Gem
Suitable for Museums,Institutions and Students of Gemology.
Beautiful sharp Catseye effect.
Large Sizes are Extremely Rare!
A Gem of Lasting Beauty.
Among the Rarest of gemstones.

Refractive Index: 1.518 – 1.526
Hardness: 6 – 6.50
Chemical Comp: KalSI3O8
Density: 2.55 – 2.57
Crystal Group: Monoclinic

Fledspar Cats-eye is characterized by an enchanting play of light. It owes its name to the Blue Sheen which looks different when the stone is turned and is known as ‘adularescence’. – Caused by the lamellar inner construction of the gemstone. Incident light rays are refracted and scattered in the stone and a unique light effect is created.

Sri Lanka is the main source country of the Blue-sheen Fledspar – the most attractive type. Some Moonstones display a single ray like a chatoyant effect and are called Cats-eyes which are rare and much sought after by Collectors.