Anthoinite

Formula:  WAlO₃(OH)₃

Origin of name:  For Raymond Anthoine (1888-1971), Belgian mineralogist

Crystal system:  Triclinic

Crystal class:  1 or -1

Twinning:

Unit cell: a = 9.21 Å, b = 11.36 Å, c = 8.26 Å, a = 94°45', b = 90°, g = 92°35'

Colour:  White (when free of iron)

Diaphaneity: Translucent

Luster: Earthy, dull

Habit:  Crystals tabular, microscopic; chalk-like masses, pseudomorphs after scheelite

Hardness:  1 (massive)

Specific gravity:  4.8

Cleavage:  1; {001} perfect

Tenacity:

Streak: White

Synonyms/varieties:

Comments: Found in placers with cassiterite and wolframite and in quartz veins with ferberite, which appears to replace it; in altered skarn.