Stellerite
Image: <a href="//commons.wikimedia.org/wiki/User:Iifar" title="User:Iifar">Ivar Leidus</a> (CC BY-SA 4.0)
Mineral NameStellerite
Chemical FormulaCa[Al2Si7O18]·7H2O
Mohs Hardness4.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {001}
Fractureuneven
Specific Gravity2.15
Colorspale orange, yellowish-orange, light orange
Transparencytranslucent
Type LocalityTakat, Imilchil, Midelt Province, Drâa-Tafilalet Region, Morocco
Mineral GroupSilicates (Zeolite group)
Usescollector's mineral
Associated Mineralschabazite-Ca
Rarityuncommon
Description
This specimen displays a prominent, radiating cluster of pale orange to yellowish-orange Stellerite crystals, forming a fan-like habit on a dark grey, granular matrix. Several smaller, blocky, light orange chabazite-Ca crystals are also present on the matrix.
Geological Context
Stellerite is a zeolite mineral typically found in amygdaloidal cavities and fractures within basaltic and other volcanic rocks, forming through hydrothermal alteration processes at low temperatures.
