Anatase
Image: Didier Descouens (CC BY-SA 4.0)
Mineral NameAnatase
Chemical FormulaTiO₂
Mohs Hardness5.5
Crystal Systemtetragonal
Lusteradamantine
Streak Colorwhite to pale yellow
Cleavageperfect on {101} and {001}
Fracturesubconchoidal to irregular
Specific Gravity3.9
Colorsblue, golden-brown, black
Transparencytranslucent
Type LocalitySt Christophe-en-Oisans, Bourg d'Oisans, Isère, Rhône-Alpes, France
Mineral GroupOxides
Usescollector, minor source of titanium
Associated Mineralsquartz, chlorite, adularia
Rarityuncommon
Description
This specimen features a sharp, bipyramidal anatase crystal displaying a striking color gradient from deep blue to golden-brown, prominently set within a matrix of smaller, light-colored, granular crystals.
Geological Context
Anatase typically forms in igneous and metamorphic rocks, often as an alteration product of other titanium minerals, and is commonly found in alpine-type fissures and hydrothermal veins.
