| Svanbergite | |
| Category: | Phosphate minerals |
| Formula: | SrAl3(PO4)(SO4)(OH)6 |
| Imasymbol: | Svb[1] |
| Strunz: | 8.BL.05 |
| System: | Trigonal |
| Class: | Hexagonal scalenohedral (m) H-M symbol: (2/m) |
| Symmetry: | Rm |
| Unit Cell: | a = 6.970–6.992 Å c = 16.567–16.75 Å, Z = 3 |
| Color: | Colorless, cream-yellow, rose, reddish brown |
| Habit: | Rhombohedral crystals (to pseudocubic); granular, massive |
| Cleavage: | Distinct on |
| Mohs: | 5 |
| Luster: | Vitreous to adamantine |
| Diaphaneity: | Translucent |
| Gravity: | 3.22 |
| Opticalprop: | Uniaxial (+) |
| Refractive: | nω = 1.631–1.635 nε= 1.646–1.649 |
| Birefringence: | δ=0.0140–0.0150 |
| References: | [2] [3] |
Svanbergite is a colorless, yellow or reddish mineral with the chemical formula SrAl3(PO4)(SO4)(OH)6. It has rhombohedral crystals.[4]
It was first described for an occurrence in Varmland, Sweden in 1854 and named for Swedish chemist Lars Fredrik Svanberg (1805–1878).[2] [3]
It occurs in high aluminium medium-grade metamorphic rocks; in bauxite deposits and from sulfate enriched argillic alteration (high silica and clay) associated with hydrothermal systems often replacing apatite. It occurs with pyrophyllite, kyanite, andalusite, lazulite, augelite, alunite, kaolinite and quartz.[2]