| Property |
Specification |
| Chemical Formula |
(Na, Ca)(Al, Fe, Mg, Li)3(Al, Cr, V)6(Si6O18)(BO3)3(OH)4 |
| Color |
Ranges from pink, green, blue, to multi-colored (bicolored, tricolored) |
| Crystal System |
Hexagonal (Trigonal) |
| Hardness |
7 to 7.5 on the Mohs scale |
| Specific Gravity |
3.06 to 3.24 |
| Refractive Index |
1.62 to 1.64 |
| Density |
2.9 to 3.2 g/cm³ |
| Cleavage |
None (fracture is irregular or conchoidal) |
| Transparency |
Transparent to opaque |
| Luster |
Vitreous (glassy) to sub-adamantine |
| Fracture |
Uneven or conchoidal |
| Occurrence |
Found in metamorphic rocks, granites, and pegmatites |
| Inclusions |
Often contains inclusions like rutile, gas bubbles, or minerals |
| Common Shapes |
Rough chunks, elongated crystals, or irregular fragments |
| Size |
Varies from small grains to large boulders |
