Ice
Chemical Formula	H2O
Species	Oxides & Hydroxides
Crystal System	Hexagonal
Mohs Scale	1
Specific Gravity	0.9167
Color	Colourless to white, pale blue to greenish blue in thick layers
Streak	White
Luster	Vitreous
Refractive Index	n = 1.320 n = 1.330
Diaphaneity	Transparent, Translucent
Fracture	Conchoidal
Crystal Habit：Usualyy as snow crystals, in complex six-rayed stellate forms of great variety, flattened . Delicate skeletal forms or hopper-shaped prisms as hoar frost. Lathlike crystals, greartly elongated at times, by crystallization on the surface of water.