Black big Star Cabs Mix

Black star is also known as black star sapphire/diopside and is a type of aluminium oxide.  When cut into a dome shape it reveals a star feature. When cut with a flat top a golden colour is revealed. Common deposits are found in Russia, Pakistan, South Africa, Austria, Brazil, Italy, North America, Sri Lanka and Finland but most commonly India.

Shape:  Oval

Size:  13.5 x 18.7 mm  

Height: 7.7 mm

Weight:  3.72 grams

Colour: black

Moh's hardness: 5.5 - 6.5

Density: 3.25 - 3.55

Cleavage: distinct/ good on

Refractive index: 1.665 - 1.73

Dispersion: Weak to distinct