Greifensteinite

Greifensteinite is beryllium phosphate mineral with formula: Ca₂Fe₅Be₄(PO₄)₆(OH)₄·6H₂O. It is the Fe dominant member of the roscherite group. It crystallizes in the monoclinic crystal system and typically forms prismatic dark olive green crystals.

It was first described in Germany at Greifenstein Rocks, Ehrenfriedersdorf, and was named for the location. At the type locality it occurs within a lithium-rich pegmatite in miarolitic cavities. It was approved by the International Mineralogical Association in 2002.