Gmelinite-Na
Image: John Sobolewski (JSS) (CC BY 3.0)
Mineral NameGmelinite-Na
Chemical Formula(Na2,Ca,K2)Al2Si4O12·6H2O
Mohs Hardness4.5
Crystal Systemhexagonal
Lustervitreous
Streak Colorwhite
Cleavagedistinct on {1010}
Fractureuneven
Specific Gravity2.1
Colorspink, white, colorless, yellow, reddish, brownish
Transparencytransparent
Type LocalityFlinders area, Victoria, Australia
Mineral GroupSilicates (Zeolite Group)
Usescollector, industrial (as a zeolite)
Associated Mineralsnatrolite, calcite, apophyllite, other zeolites
Rarityuncommon
Description
A mass of pink, hexagonal gmelinite-Na crystals, some associated with delicate white natrolite needles.
Geological Context
Gmelinite-Na is a zeolite mineral typically found in the cavities of basaltic and other volcanic rocks, forming as a secondary mineral during hydrothermal alteration.
