Formula: TiO2
Simple oxide, polymorph of brookite and
rutile.
Specific gravity: 3.79 to 3.97
Hardness: 5½ to 6
Streak: White to pale yellow
Colour: Brown, pale yellow or reddish brown, indigo, black; pale green, pale lilac, grey,
rarely nearly colourless; brown, yellow-brown, pale green, blue in transmitted light.
Solubility: Insoluble in acids
(Dana)
Environments:
Igneous environments
Pegmatites
Carbonatites
Sedimentary environments
Metamorphic environments
Hydrothermal environments
Anatase is usually secondary, derived from other titanium-bearing minerals. In Alpine veins it is
derived from the enclosing gneiss or
schist by leaching by hydrothermal solutions. In also
occurs in igneous and
metamorphic rocks, in pegmatites and carbonatites. It is a common detrital mineral
(HOM, Dana).
Common associates include brookite,
rutile, titanite,
ilmenite, titanium-rich
magnetite, hematite,
quartz, adularia and
chlorite
(HOM) Mindat Dana).
At the Marcil quarry, near Ste-Clotilde-de-Châteauguay, Quebec, Canada, anatase has been found associated
with quartz and dolomite.
The mineral is formed early in the paragenetic sequence, appearing to have preceded
quartz
(R&M 86.6.549).
At the type locality, St Christophe-en-Oisans, Auvergne-Rhône-Alpes, France, anatase occurs in Alpine
veins, derived from the enclosing gneiss or
schist by hydrothermal solutions
(Mindat).
At the the Santo Nino Mine, Santa Cruz County, Arizona, USA, anatase occurs in association with
quartz, muscovite,
sericite and
adularia
(R&M 87.2.126).
At Placerville, California, USA, anatase occurs with brookite
on quartz
(Dana).
At Quincy, Massachusetts, USA, anatase occurs in pockets in a pegmatite with
aegirine, fluorite
and ilmenite
(Dana).
Near diabase dikes at Somerville, Massachusetts, USA, anatase occurs with
brookite and titanite
(Dana).
At Arvon, Buckingham county, Virginia, USA, anatase is found in joint planes in
slate with quartz
and pyrite
(Dana).
Common impurities: Fe,Sn,V,Nb
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