Species: Corundum 
Hardness: 9 
Refractive Index (RI): 1.762~1.770 
Color: Light to Dark Red, pinkish/Purplish Red 
Occurrence: Burma, Thailand, Pakistan, Vietnam, Ceylon, Africa.

Species: Fresh Water, Salt Water 
Hardness: Varies 
Refractive Index (RI): Not Applicable (Opaque) 
Color: White, Grey, Yellowish - White, Light - Cream, Black, Body - Color 
Occurrence: Seas of Basra, South Sea, Tahiti, Arabia, Australia, Japan, Bahrain, Persia.

Species: Corundum 
Hardness: 9 
Refractive Index (RI) : 1.762~1.770 
Color: Light to Dark Blue, Violetish - Blue, Greenish - Blue, Purplish - Blue 
Occurrence: Kashmir, Burma, Thailand, Pakistan, Vietnam, Ceylon, Africa, Australia.

Species: Corundum 
Hardness: 9 
Refractive Index (RI) : 1.762~1.770 
Color: Light to Dark Yellow, Pale - Yellow, Orangish Golden - Yellow 
Occurrence: Sir - Lanka, Burma, Thailand, Cambodia, Africa, Australia.

Species: Chrysoberyl 
Hardness: 7.5-8 
Refractive Index (RI): 1.577~1.583 
Color: Light to Dark Green. 
Occurrence: Colombia, Brazil, Russia, India.

Species: Grossularite 
Hardness: 7 - 7.5 
Refractive Idex (RI): 1.740 
Color: Brown, Brownish - Orange, Orangish - Brown. 
Occurrence: Sri Lanka, Canada, Canada, Brazil. Africa, Madagascar.

Species: Corundum 
Hardness: 3.5 - 4.0 
Refractive Index (RI) : Not Applicable as they are Opaque 
Color: Flesh Pink, Dark Blood Red, Orange, Orangish - Red, Brownish - Red 
Occurrence: Mediterranean Sea, Red Sea, Sea near Spain, Morocco, Malaysia, Japan.

Species: Chrysoberyl 
Hardness: 8.5 
Refractive Index (RI): 1.744~1.755 
Color: Light to Dark Greenish - Yellow, Green, Brownish – Green, Brownish - Yellow. 
Occurrence: Sri Lanka, Brazil, Russia, Tanzania, China.

Species: Carbon 
Hardness: 10 
Refractive Index (RI): 2.417 
Color: Colorless, Yellow, Brown, Red, Green, blue, other Fancy Colors 
Occurrence: Africa, Russia, Canada, Australia, India.