Thulite
Thulite is a rare member of the Epidote Group of minerals that includes Allanite, Clinozoisite, Epidote, Hancockite, Mukhinite, Piedmontite, Tanzanite, Thulite and Zoisite. Thulite is a beautiful, deep pink, manganoan variety of Zoisite and found mainly in Norway but also found in small quantities from other locations around the world. Thulite was first discovered in Kleppan, Sauland, Hjartdal Telemark, Norway in 1820. It is often mottled with white calcite and the pink to red color is due to its manganese content. Thulite is the national gemstone of Norway and they pronounce it “too leat”.
| Category: | Epidote |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals prismatic, to 10 cm, typically deeply striated and poorly terminated; columnar to compact, massive (Thulite). |
| Twinning: | None |
| Cleavage: | [001] Perfect |
| Fracture: | Even, Uneven, Conchoidal |
| Tenacity: | Brittle |
| Hardness (Mohs): | 6.0 – 6.5 |
| Density: | 3.09 – 3.30 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Pink, deep Pink, Rose Red, Red |
| Transparency: | Transparent to Sub-Translucent |
| Luster: | Vitreous, Pearly |
| Refractive Index: | 1.695 – 1.701 Biaxial ( + ) |
| Birefringence: | 0.0060 – 0.0180 |
| Dispersion: | Relatively Strong; 0.019 |
| Pleochroism: | None |
