Grossmanite is a very rare mineral of the pyroxene group,Mindat, Grossmanite, http://www.mindat.org/min-39426.html with formula CaTi³⁺AlSiO₆. 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 ...

, Ti₂O₃.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 {{silicate-mineral-stub