Gehlenite
| Gehlenite | |
|---|---|
| General | |
| Category | Sorosilicates |
| Formula | Ca2Al[AlSiO7] |
| IMA symbol | Gh |
| Strunz classification | 9.BB.10 |
| Crystal system | Tetragonal |
| Crystal class | Scalenohedral (42m) H-M symbol: (4 2m) |
| Space group | P421m |
| Identification | |
| Colour | yellow-brown, green-grey, colourless |
| Cleavage | Distinct/good |
| Mohs scale hardness | 5–6 |
| Lustre | vitreous, greasy |
| Streak | white, grey-white |
| Birefringence | δ = 0.010 |
Gehlenite, (Ca2Al[AlSiO7]), is a sorosilicate, Al-rich endmember of the melilite complete solid solution series with akermanite. The type locality is in the Monzoni Mountains, Fassa Valley in Trentino in Italy, and is named after the Adolf Ferdinand Gehlen (1775–1815) by A.J. Fuchs in 1815.