:Locality: Fumade, Tarn, Midi-Pyrénées, France Size: 2.1 × 1.8 × 1.6 cm Description: Afmite is a rare aluminium phosphate named after of my beloved Association Française de Microminéralogie (AFM, IMA 2005-025a), but approved in 2010. In this sample we can enjoy rich groups of "open book" white (they are transparent) aggregates of tabular crystals. From the Type Locality and one of the only three localities known worldwide. — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Afmite
Afmite is phosphate mineral with the chemical formula Al3(OH)4(PO4)(PO3OH)·H2O. It is named for the French mineralogy group Association Française de Microminéralogie, or AFM for short.
Intro adapted from Wikipedia (CC BY-SA).
Afmite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al₃(OH)₄(H₂O)₃(PO₄)(PO₃OH)·H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 1.5; specific gravity 2.39; White streak; Pearly; dull on weathered surfaces luster.
IMA symbol Afm, IMA status: approved, named in 2005.
A secondary mineral formed by remobilization and crystallization during low- temperature hydrothermal activity and/or weathering and ground water activity.
It is found associated with Matulaite, variscite (France); kobokoboite (Democratic Republic of Congo).
The mineral was named to honor the Association Française de Microminéralogie (AFM), an amateur association devoted to the collection and study of micro-minerals.