Greifensteinite

greifensteinite

roscherite

childrenite

ludlamite

Images

Formula: Ca2Be4Fe2+5(PO4)6(OH)4.6H2O
Hydrated phosphate, roscherite group, beryllium-bearing mineral
Crystal System: Monoclinic
Specific gravity: 2.93 meeasured, 2.95 calculated
Hardness: 4½
Streak: Green
Colour: Dark olive green
Environments:

Pegmatites

Greifensteinite is a rare secondary mineral in miarolitic cavities in lithium-rich granite pegmatites (Webmin). Associated minerals include schröckingerite, baylissite, monohydrocalcite and calcite (HOM).

Localities

At the type locality, the Greifenstein Rocks, Ehrenfriedersdorf, Erzgebirgskreis, Saxony, Germany, greifensteinite occurs in a lithium-rich granite pegmatite, associated with albite, K-feldspar, roscherite, viitaniemiite, childrenite, quartz, apatite, herderite, elbaite and montmorillonite (Minrec 35.4.351).

Greifensteinite from Greifenstein - Image

At the the Chickering Mine, Walpole, Cheshire County, New Hampshire, USA, greifensteinite typically forms crystal clusters to 2 mm across in the vugs of siderite and quartz, associated with beraunite, strunzite and childrenite. Sprays of lathlike crystals to 0.5 mm have been identified in the hydrothermally altered triphylite assemblage, where they are associated with whitmoreite, ludlamite and paravauxite (R&M 90.5.417-418).

Griefensteinite has been reported from the Charles Davis Mine and Palermo No. 1 Mine, Groton, Grafton County, New Hampshire, and the Chandlers Mill Quarry, Newport, Sullivan county, New Hampshire, USA. In New Hampshire it occurs as pale green to green monoclinic crystals of less than 1 mm. The crystals generally appear hexagonal and are often arranged in radiating groups, sometimes spheres. It and other members of the roscherite group are relatively rare because beryllium and phosphate are needed to form minerals of this group, and that combination is an unusual one in New Hampshire pegmatites (R&M 97.3.230-231}.

Greifensteinite from the Palermo No. 1 Mine - Image

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