Griphite (Size: 7.5 x 6.4 x 3.8 cm) Locality: Everly Mine (Riverton lode), Harney City, Pennington County, South Dakota, USA Griphite is a very rare lithium phosphate found at only three localities worldwide, according to MINDAT. This waxy lustre, dark brown to gray piece is nearly solid griphite and is from the Type Locality - the Everly Mine of South Dakota. Older and seldom available material from the Dennis Mullane Collection. Certainly not pretty to look at, but still it’s a very rich and highly representative example of the rare species. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Griphite
Griphite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Ca(Mn²⁺,Na,Li)₆Fe²⁺Al₂(PO₄)₆(F,OH)₂.
It crystallizes in the cubic crystal system (space group Pa3).
Key properties: Mohs hardness 5.5; specific gravity 3.4–3.64; Resinous to vitreous luster.
IMA symbol Gph, grandfathered status — known before the IMA’s founding, named in 1891.
An accessory mineral in complex granite pegmatites.
It is found associated with Crandallite, apatite, montebrasite, triplite, hausmannite, albite, mica, quartz.
Its name comes from the Greek for enigma, as the chemical composition was originally puzzling.