Akaogiite (
IMA symbol
A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...
Aka
) is an exceedingly rare mineral, one of the natural forms of
titanium dioxide
Titanium dioxide, also known as titanium(IV) oxide or titania , is the inorganic compound with the chemical formula . When used as a pigment, it is called titanium white, Pigment White 6 (PW6), or CI 77891. It is a white solid that is insolu ...
(TiO
2). It is a high-pressure
polymorph of TiO
2, along with
anatase
Anatase is a metastable mineral form of titanium dioxide (TiO2) with a tetragonal crystal structure. Although colorless or white when pure, anatase in nature is usually a black solid due to impurities. Three other polymorphs (or mineral form ...
,
brookite and another high-pressure phase called "TiO
2 II".
Rutile
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite.
Rutile has one of the highest refractive indices at visib ...
is the stable polymorph of TiO
2, most commonly found at standard temperatures and pressures.
Akaogiite can be found at the
Nördlinger Ries Crater, a
meteor crater
Meteor Crater, or Barringer Crater, is a meteorite impact crater about east of Flagstaff and west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are offi ...
in Germany, where the extreme pressure during the impact allowed its formation.
References
Oxide minerals
Titanium minerals
Monoclinic minerals
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