groutite

groutite

[′grau̇‚tīt]
(mineralogy)
HMnO2 A mineral of the diaspore group, composed of manganese, hydrogen, and oxygen; it is polymorphous with manganite.
References in periodicals archive ?
The main minerals of this group are: Brucite, Geothite, Diaspore, Bauxite, Lepidocrocite, Manganite, Groutite, Stainierite and Chalcopanite that this project discusses the diaspore minerals and processing of them from the diaspore minerals.
In January 2006, some local collectors gained temporary access to old underground workings somewhere in the Ilfeld district (see under "Collecting Manganite"), and a very few of the 300 or so fair-to-good specimens of manganite which they extracted sport black, free-standing, leafy crystals of groutite (www.
The matrix is massive black manganite, and there are some subhedral white barite crystals, and, on a very few of the specimens, 2-cm metallic black crystals of the rare species groutite.
Also, according to Gunnar, free-standing, 2-cm black crystals of the rare species groutite have been spotted on a few specimens from the find.
The vesuvianite is accompanied rarely by transparent, colorless diopside in tabular crystals to more than 1 cm, and by small, black needles of groutite or small prisms of manganite.