Chemical composition -- Calcium fluoride.
Color -- Almost any color.
Optics -- R.I 1.43.
Durability -- Hardness 4, with easy cleavage. Not durable enough for use in jewelry.
Crystal structure -- Isometric.
Specific Gravity -- 3.18.
Sources -- Many sources worldwide. Often found in very large sizes. Due to the extreme variations in color and some difficulties in cutting, fluorite makes an interesting collector's stone.