Stellerite | |
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General | |
Category | Zeolite mineral |
Formula (repeating unit) | Ca(Al2Si7O18)•7H20 |
IMA symbol | Ste[1] |
Strunz classification | 9.GE.15 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
Space group | Fmmm |
Identification | |
Color | Colorless to white, pink, orange |
Crystal habit | Spherical, Stellate, Tabular |
Cleavage | Perfect on {010} |
Fracture | Uneven |
Mohs scale hardness | 4.5 |
Luster | Pearly |
Streak | white |
Diaphaneity | Transparent to translucent |
Specific gravity | approximately 2.2 |
Density | 2.13 g/cm3 |
Optical properties | Biaxial (-), a=1.4848, b=1.4864-1.4964, g=1.4979 |
Birefringence | δ = 0.013 |
References | [2] |
Stellerite is a rare mineral discovered by and named after Georg Wilhelm Steller, a German explorer and zoologist.[2] The mineral has a general formula of Ca[Al2Si7O18]·7H2O.[3] Like most rare minerals, there are few commercial uses for stellerite. Mineral collectors are lucky to find it in good enough crystal form. Zeolites, including stellerite, have been studied using a dehydration process to gauge the potential use of their phases as molecular sieves, sorbents, and catalysts.[4] Its occurrences are in cavities of andesite as sheaf-like clusters of small crystals.[2]