Anatase is one of the three main polymorph forms of TiO2, three minerals
with the same composition but different structure, rutile and brookite
being the other two.
Anatase is a typical collector mineral because its abundance and the
hige variety of colours and forms. Crystals of anatase are usually sub
millimetric and nice crystals are very rare. Quartz with nice size crystals
of anatase are really rare.
Anatase in quartz comes mainly from Brazil and can be honey color or
blue. Often anatase crystals are associated with epitactic rutile forming
a kind of star shaped association with the anatase in the middle and the
rutile needles crossing the anatase with an angle of 60 degres.
Main deposit of cutting quartz material with brookite inclusions comes
from the area of Diamantina, Jequitinhonha Valley, between Gouveia and
Corinto, in Minas Gerais, Brazil.