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; it has 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, Ti₂O₃.Mindat, Tistarite, http://www.mindat.org/min-38695.html Titanium in minerals is almost exclusively tetravalent. Grossmanite stands for titanium-analogue of

davisite Davisite is an exceedingly rare mineral of the pyroxene group, with formula CaScAlSiO6. It is the scandium-dominant member.Mindat, http://www.mindat.org/min-38829.html It stands for scandium-analogue of other pyroxene-group members, esseneite, gro ...

esseneite Esseneite is a relative rare mineral of the pyroxene group, with formula CaFeAlSiO6. It is the ferric-iron-dominant member. Esseneite is an iron-analogue of other pyroxene-group members, davisite, grossmanite, and kushiroite. It is a metamorphic mi ...

and kushiroite – other members of the pyroxene group. Both grossmanite and tistarite come from the famous Allende meteorite.

References

Pyroxene group Inosilicates Calcium minerals Titanium minerals Aluminium minerals Monoclinic minerals {{silicate-mineral-stub