Stilbite-Ca

stilbite-Ca

stilbite

zeolite

prehnite

Images

Formula: NaCa4(Si27Al9)O72 .28H2O
Tectosilicate (framework silicate), stilbite subgroup of the zeolite group
Crystal System: Monoclinic (pseudo orthorhombic)
Specific gravity: 2.19 measured, 2.23 calculated
Hardness: 3½ to 4
Streak: White
Colour: White, red, yellow, brown, cream
Luminescence: May fluoresce pale-yellow or blue-white in short wave UV
Solubility: Moderately soluble in hydrochloric acid
Environments:

Metamorphic environments
Basaltic cavities

Stilbite-Ca is a low-temperature hydrothermal mineral occurring in amygdaloidal cavities in basalts, andesites, and various metamorphic rocks. Formed in hot springs deposits, and as a cementing agent in some sandstones and conglomerates. Associated minerals include zeolites, prehnite, calcite and quartz (HOM).

Localities

At Wasson Bluff, Two Islands, Cumberland County, Nova Scotia, Canada, exellent fans of orange stilbite have been found (Mindat photo).
Stilbite-(Ca) from Wasson Bluff - Image

At the Houdaille Quarry, Springfield, Springfield Township, Union County, New Jersey, USA, stilbite-Ca has been found with heulandite (Mindat photo).
Stilbite-Ca from the Houdaille Quarry - Image

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