Anthoinite , Ferberite (Var: Reinite ) Dimensions: 4.7 x 3.3 x 2.4 cm. Locality: Bugarama Mine, Northern Province, Rwanda Description: Anthoinite is a very rare anhydrous tungstate and this very rare and weird looking combination is from an obscure Rwanda locale, an unusual Al-rich phosphate pegmatite. It is rare from any world-wide locale. Striking box-works on three sides of the matrix are filled with straw-yellow anthoinite. The matrix is a real rarity in itself. Reinite is a rare ferberite varietal, that pseudomorphs scheelite crystals. This is a large, partially euhedral pseudomorph with two sharp faces. Choice very rare material, probably mined in the 1950s or 1960s, from the Matioli Collection. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Anthoinite
An aluminium-tungsten oxide mineral first found in Maniema, Democratic Republic of the Congo.
Intro adapted from Wikipedia (CC BY-SA).
Anthoinite is an IMA-recognized mineral species in the tungstate class, with the chemical formula AlWO₃(OH)₃.
It crystallizes in the triclinic crystal system (space group I-1). It is a member of the Anthoinite structural group.
Key properties: Mohs hardness 1; specific gravity 4.78–4.87; Dull luster.
IMA symbol Atn, grandfathered status — known before the IMA’s founding, named in 1947.
Found in placers with cassiterite and wolframite and in quartz veins with ferberite, which appears to replace it (Mt. Misobo mine, Congo); in altered skarn (Kara mine, Tasmania).
It is found associated with Ferberite, scheelite (Mt. Misobo mine, Congo); mpororoite, scheelite (Kara mine, Tasmania); raspite, ferberite, ferritungstite (Gifurwe mines.
The name refers to Raymond Anthoine (1884–?), Belgian mining engineer.