| Humite | |
| Category: | Nesosilicates |
| Formula: | (Mg,Fe)7(SiO4)3(F,OH)2. |
| Imasymbol: | Hu[1] |
| Strunz: | 9.AF.50 |
| System: | Orthorhombic |
| Class: | Dipyramidal (mmm) H–M Symbol: (2/m 2/m 2/m) |
| Symmetry: | Pbnm |
| Unit Cell: | a = 10.24, b = 20.72 c = 4.73 [Å]; Z = 4 |
| Color: | White, yellow, dark orange, brown |
| Cleavage: | Poor |
| Fracture: | Uneven to subconchoidal |
| Tenacity: | Brittle |
| Mohs: | 6–6.5 |
| Luster: | Vitreous |
| Refractive: | nα =1.607–1.643, nβ=1.619–1.653, nγ=1.639–1.675 |
| Opticalprop: | Biaxial (+) |
| Birefringence: | 0.0320 |
| Dispersion: | Weak, r > v |
| 2V: | Calculated = 70–78°, measured = 68–81° |
| Streak: | White |
| Gravity: | 3.20 – 3.32 |
| Diaphaneity: | Transparent |
| References: | [2] [3] [4] |
Humite is a mineral found in the volcanically ejected masses of Vesuvius. It was first described in 1813 and named for Abraham Hume (1749–1838).[5]