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Download hereGENERAL DESCRIPTION
Henritermierite belongs to the group of garnets: it is a silicate with the rather rare trivalent manganese.
It is presented as small grains (pseudo-octahedral crystals), brown-orange, in interstice with other minerals among manganese deposits.
It was discovered so far only 2 deposits. Both are manganese deposits: Tachgagalt, Anti-Atlas massif in Morocco and the Chwaning and Wessels mines of the manganiferous fields of the Kalahari, in the Republic of South Africa. Henritermierite is associated with marokite, hausmannite and gaudefroyite in the Moroccan mine and with hausmannite, manganite and andradite in the South African mines.
The types of this species are kept in various places : the Ecole des Mines in Paris, sample given by François Permingeat in 1970 and the Museum national d’Histoire naturelle in Paris, sample given by Christophe Gaudefroy. Two other type samples are kept in Toulouse, France and in Rabat, Morocco.
HISTORY : Species dedicated to Pr. Henri Termier (1897-1989), French geologist
Species first described in 1969 by C. Gaudrefoy (1888-1971) et al.
Type-locality: Mine Tachgagalt, Ourzazat, Morocco
CHEMICAL FORMULA : Ca3 (Mn, Al)2 (SiO4)2 (OH)4
CRYSTAL SYSTEM : Tetragonal
COLOR : Brown-orangeish, yellow
DIAPHANIETY : Translucent
LUSTER : Vitreous
STREAK : White
MORPHOLOGIE : Pseudo-octahedric crystals, aggregates, granular
HARDNESS : 4
CHEMICAL CLASS: 3,34
DENSITY : VIII - Silicates
GROUP : Garnet
STRUNZ CLASS BEFORE 2001 : 8/A.08-160
STRUNZ CLASS AFTER 2001 : 9.AD.15
