Gmelinite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameGmelinite
Chemical Formula(Na2,Ca,K2)Al2Si4O12·6H2O
Mohs Hardness4.5
Crystal Systemhexagonal
Lustervitreous
Streak Colorwhite
Cleavagedistinct on {1010}
Fractureuneven to conchoidal
Specific Gravity2.04
Colorswhite, colorless, yellowish, reddish, brownish
Transparencytransparent to translucent
Type LocalityWasson Bluff, Parrsboro, Bay of Fundy, Cumberland County, Nova Scotia, Canada
Mineral GroupSilicates (Zeolite Group)
Usescollector, industrial (as a zeolite for adsorption/ion-exchange)
Associated Mineralschabazite, calcite, other zeolites
Rarityuncommon
Description
This specimen features well-formed, tabular hexagonal crystals of Gmelinite, ranging from colorless to white and pale yellowish, often associated with reddish-brown Chabazite-Ca.
Geological Context
Gmelinite is a zeolite mineral that typically forms in amygdaloidal cavities and veins within basaltic volcanic rocks, often as a product of low-temperature hydrothermal alteration.
