Grossmanite is a very rare mineral of the pyroxene group,
[Mindat, Grossmanite, http://www.mindat.org/min-39426.html] with formula CaTi
3+AlSiO
6. It is the
titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...
-dominant member. Grossmanite is unique in being a mineral with trivalent titanium, a feature shared with
tistarite
Tistarite is an exceedingly rare mineral with the formula Ti2O3, thus being the natural analogue of titanium(III) oxide.Mindat, Tistarite, http://www.mindat.org/min-38695.html In terms of chemistry it is the titanium-analogue of hematite, corundum ...
, Ti
2O
3.
[Mindat, Tistarite, http://www.mindat.org/min-38695.html] Titanium in minerals is almost exclusively tetravalent. Grossmanite stands for titanium-analogue of
davisite,
esseneite and
kushiroite - other members of the pyroxene group. Both grossmanite and tistarite come from the famous
Allende meteorite
The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After it broke up in the atmosphere, an extensive search for ...
.
References
Pyroxene group
Inosilicates
Calcium minerals
Titanium minerals
Aluminium minerals
Monoclinic minerals
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