| Other names: | Amphibole (see Hornblende) |
| Mineral class: | Inosilicate, double chain |
| Composition: | Ca2(Mg, Fe)5Si8O22(OH)2 |
| Hardness: | 5 - 6 |
| Luster: | Vitreous |
| Color: | Pale to dark green or black. White when pure. |
| Streak: | Pale green or white |
| Cleavage: | 2 good planes at 56 and 124 degrees |
| Crystal form: | Long, 6-sided crystals, fibrous or in aggregates |