| Hodgkinsonite | |
| Category: | Nesosilicate |
| Formula: | Zn2MnSiO4(OH)2 |
| Imasymbol: | Hgk[1] |
| Strunz: | 9.AE.20 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | P21/a |
| Unit Cell: | a = 11.76, b = 5.31 c = 8.18 [Å]; β = 95.42°, Z = 4 |
| Mohs: | - 5 |
| Opticalprop: | Biaxial (-) |
| Refractive: | nα = 1.720 nβ = 1.741 nγ = 1.746 |
| Birefringence: | δ = 0.026 |
| Dispersion: | r < v moderate |
Hodgkinsonite is a rare zinc manganese silicate mineral Zn2MnSiO4(OH)2. It crystallizes in the monoclinic system and typically forms radiating to acicular prismatic crystals with variable color from pink, yellow-red to deep red. Hodgkinsonite was discovered in 1913 by H. H. Hodgkinson, for whom it is named in Franklin, New Jersey, and it is only found in that area.[2]