Grossite

General
Category| Oxide minerals
Formula
(repeating unit)| CaAl4O7
Strunz classification| 4.CC.15
Dana classification| 07.03.02.01
Crystal system| Monoclinic
Crystal class| Prismatic (2/m)
(same H-M symbol)
Space group| C2/c
Unit cell| a = 12.94, b = 8.91
c = 5.44 [Å]; β = 107.01°; Z = 4
Identification
Color| Colorless to white
Crystal habit| Lathlike or subhedral rounded grains in polycrystalline aggregates rimmed by melilite (in meteorites)
|re|er}}| Vitreous
Streak| White
Diaphaneity| Transparent
Specific gravity| 2.88
Optical properties| Biaxial (+)
Refractive index| nα = 1.618 nβ = 1.618 nγ = 1.652
Birefringence| δ = 0.034
2V angle| Measured: 15°
References| [1][2][3]

Grossite is a calcium aluminium oxide mineral with formula CaAl4O7. It is a colorless to white vitreous mineral which crystallizes in the monoclinic crystal system.[2][3]

Grossite was first described 1994 for an occurrence in the Hatrurim Formation of Israel. It was named for Shulamit Gross (1923–2012) of the Geological Survey of Israel.[1][3]

It occurs within high temperature metamorphosed impure limestone of the Hatrurim Formation and also within calcium-aluminium rich inclusions in chondritic meteorites. Associated minerals in the Hatrurium include brownmillerite, mayenite and larnite. In meteorites it occurs with perovskite, melilite, hibonite, spinel and calcium rich pyroxene.[1]

## See also

* Glossary of meteoritics

## References

1. ↑ 1.0 1.1 1.2 Handbook of Mineralogy
2. ↑ 2.0 2.1 Mindat.org
3. ↑ 3.0 3.1 3.2 Webmineral data
4. ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Grossite. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Grossite&oldid=338252"