Gmelinite
Chemical Formula	Na4(Si8Al4)O24·11H2O[1]
Species	Silicates
Crystal System	Hexagonal
Mohs Scale	4.5
Specific Gravity	2.04-2.17
Color	Colorless, white, yellow, orange, pale green, pink, red, brown and grey
Streak	White
Luster	Dull to vitreous
Refractive Index	nω = 1.476 - 1.494, nε = 1.474 - 1.480[2]
Diaphaneity	Transparent, translucent or opaque
Cleavage	Good on
Fracture	Conchoidal
Crystal Habit：Hexagonal plates, or short prisms, showing hexagonal dipyramids, pyramids and basal pinacoid. {1010}, {1011} and {0001} dominant. May also be tabular or rhombohedral. Crystals are striated parallel to (0001)