| Barrerite | |
| Category: | Zeolite |
| Formula: | (Na,K,Ca)2Al2Si7O18·6(H2O) |
| Imasymbol: | Bre[1] |
| Strunz: | 9.GE.15 |
| Color: | White, pink |
| System: | Orthorhombic |
| Class: | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Symmetry: | Amma |
| Cleavage: | Perfect |
| Mohs: | 3 - 4 |
| Luster: | Vitreous-glassy |
| Diaphaneity: | Transparent to translucent |
| Streak: | White |
| Refractive: | nα = 1.479 nβ = 1.485 nγ = 1.489 |
| Opticalprop: | Biaxial (-) |
| Gravity: | 2.13 |
| References: | [2] [3] [4] |
Barrerite is a tectosilicate mineral and a member of the zeolite family. It is one of the rarer zeolites. It was named for Richard Barrer, a New Zealand-born chemist.[4]
Barrerite crystal are white to pinkish, with a vitreous-glassy luster. The crystal system is orthorhombic and is flat and tabular in appearance. It has a Mohs hardness of 3 to 4 and its cleavage is perfect. Barrerite has a white streak and a density of 2.13.
It was first described in 1974 for an occurrence in Sardinia at Sant' Efisio Tower on Cape Pula in Cagliari Province.[4] It has also been reported from Rocky Pass, Kuiu Island, Alaska, and a few other localities.