Anatase - Encyclopedia

    Class : Oxides and hydroxides
    Subclass : Oxides
    Crystal system : Tetragonal
    Chemistry : TiO2
    Rarity : Rare

Anatase is a titanium oxide, a rutile polymorph. Although much rarer than the latter, it is typically found in alpine fissures and some metamorphic rocks of greenschist and amphibolite facies, and more rarely in some pegmatites and carbonatites. It takes its name from the Greek anatasis (extension) in reference to a particularly developed axis of elongation compared to other tetragonal minerals. Anatase forms acute or more rarely obtuse octahedra, sometimes tabular, rarely prismatic with often horizontally striated faces (characteristic alpine facies), as well as flattened crystals sometimes terminated by a double pyramide. It is a transparent to translucent mineral, sometimes opaque with almost metallic adamantine lustre. Its color is usually yellow honey to dark brown or black, sometimes gray to dark blue. The crystals are small, rarely centimetric. Anatase is popular with mineral collectors but without special uses.

Anatase (19 mm) on quartz of Pointe du Rozet, Savoie, France
Blue anatase on chloritic quartz from Pakistan
Anatases from Dyrfonni, Viveli, Eidfjord, Hardangervidda, Norway
Anatases from the Plan du Lac, Isère, France

Anatase in the World

The best anatase crystals come from Brazil with 5 cm black elongated octahedra in Minas Novas (Minas Gerais) and alpine fissures in the Binn Valley in Switzerland where 5 cm prismatic or tabular honey crystals, sometimes gems, are probably the most beautiful in the world. Norway with Hardan Gervidda also produced very beautiful crystals larger than 3 cm, more chunky (main photo). Finally we must emphasize the centimetric crystals of Pakistani pegmatites.

Anatase in France

The Alpine fissures of the French Alps have produced very beautiful anatases. The black octahedral crystals of the Plan du Lac near St-Christophe-en-Oisans (Isère) can reach 12 mm and the black-brown octahedra of the Col de la Madeleine (Savoie) near 30 mm (left photo). It is found more anecdotally in microcrystals in the alluvial deposits of some rivers of Haute-Loire and Cantal in especially.

Twinning and special forms

Rare on {112} and usually visible on small crystals. See photo on the right, twinned anatase specimen from Solumsasen Quarry, Holmestrand, Norway (copyright Enrico Bonacina - Source Mindat).

Fakes and scams

There are no fake records for this species.



Hardness : 5.5 to 6
Density : 3.9 to 4
Fracture : Sub-conchoidal
Trace : White, yellow, grey




TP : Transparent to opaque
IR : 2.488 to 2.561
Birefringence : 0.073
Optical character : Uniaxial -
Pleochroism : Weak to strong
Fluorescence : None


Solubility : Insoluble

Magnetism : None
Radioactivity : None