Lot of 3 rough sapphires

Sapphire is a variety of corundum which takes its name from the Greek " sappheiros " which means " blue colored stone ". It is composed ofaluminum oxide andimpurities(oxides) that determine its color. The shades vary from blue to mauve, passing by green, yellow-orange, purple or pink. Crystals are sometimes colorless. Some sapphires are heated to improve their color(traditional heating or diffusion treatment).

Sapphire is found all over the world: Madagascar, Myanmar, Sri Lanka, Australia, Kashmir, Cambodia, China, Colombia, Kenya, United States, Nigeria, Thailand, Tanzania, Vietnam, Laos, Cambodia.

• Hardness MOHS scale: 9
• Chemical Formula: Al2O3
• Luster: Vitreous