Cervantite (incl.)
Cervantite is a oxide that is rare that is formed from the oxidation of Stibnite. It is usually found as minute acicular crystal clusters or material that is massive rarely as fine needle inclusions in Quartz. These inclusions in Quartz lead to beautiful gems showing bright needles which are yellow.
Cervantite is found in several locations worldwide but the occurance that is main of needle inclusions in Quartz is Minas Gerais, Brazil.
| Chemical Formula: | Sb3+Sb5+O4 |
| Antimony Oxide | |
| Molecular Weight: | 521.21 gm |
| Composition: | Antimony | 79.19 % | Sb | 47.40 % | Sb2O3 / 52.60 % Sb2O5 |
| Oxygen | 20.81 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Pyramidal |
| Crystal Habit: | Minute acicular crystals, massive. |
| Twinning: | None observed. |
| Cleavage: | Perfect on {001}, Distinct on {100} |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 4.0 – 5.0 |
| Density: | 6.50 – 6.64 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Yellow, off-White, Reddish-White; Colorless in transmitted light |
| Transparency: | Semi-Translucent |
| Luster: | Greasy, Pearly; Earthy when powdery |
| Refractive Index: | 2.000 – 2.100 Biaxial ( ? ) |
| Birefringence: | 0.100 |
| Dispersion: | Relatively Weak |
| Pleochroism: | None |
