Detailed information
Species
Hydroxylherderite , Albite
Dimensions
28 x 21 x 14
mm
Locality
Barra do Salinas, Coronel Murta Jequitinhonha Valley Minas Gerais, Brazil
Condition
No recorded repairs
An interesting thumbnail twin of a creamy, opaque Hydroxylherderite crystal measuring to 2.8 cm, from Barro do Salinas in Coronel Murta, Brazil. Hydroxylherderite is a calcium-beryllium phosphate hydroxide [CaBe(PO4)(OH)] whereas Herderite is a calcium-beryllium phosphate fluoride [CaBe(PO4)F], hence the “Hydroxyl” prefix signifying the dominance of hydroxide over fluorine. It is a species associated with granite pegmatites, typically occurring as small indistinct crystals, hence specimens such as this are exceptional for the species.