| Mineral | ASTROPHYLLITE |
| Chemistry | (KNa) 3 (FeMn) 7 Ti 2 Si 8 O 24 (OOH) 7 |
| Class | Silicates |
| Uses | mineral specimen |
| Color | Bronze-Yellow golden Yellow . |
| Luster | Sub-Metallic |
| CrystalSystem | Triclinic |
| CrystalHabits | include small tabular or bladed crystals often grouped in starlike aggregates.Also found in lamellar massives. |
| Fracture | perfect in one direction. |
| Hardness | 3 |
| Characteristics | color is often patchy or heterogenous in distribution. |
| Occurences | include Kola Penensula, Khibina, Russia; Colorado, USA and Mt St. Hilaire, Quebec, Canada. |
| Indicators | brittleness, cleavage, color, luster and localities. |
| IMAStatus | Approved |
| Discovered | 1854 |
| CellParameters | a = 11.72b = 5.41c = 21.14 α=90°β=94°γ=90° |
| Ratio | a:b:c = 2.166 : 1 : 3.908 |
| OpticalType | Biaxial (+) |
| RI | n α =1.680 n β =1.700 n γ =1.730 |
| Birefringence | δ=0.050 |
| SurfaceRelief | High |
| TypeLocality | Langesundsfjorden Larvik Vestfold Norway |
| Strunz | 8/G.12-40 8 : Silicates G : Intermediate between chain- and layered silicates 12 : Astrophyllite- Kupletskite group |
