Cleavelandite
Cleavelandite is a platy variety of Albite which is a known user associated with the Feldspar Group of minerals that includes Albite, Amazonite, Andesine, Anorthite, Bytownite, Hyalophane, Labradorite, Moonstone, Oligoclase, Orthoclase, Sanidine, and Sunstone. Cleavelandite is not just a variety that is gemmy forms a very attractive addition to Quartz. Round, white “snowball” Cleavelandite inclusions in faceted Quartz are extremely collectible. Although Albite is extensive, Cleavelandite inclusions in Quartz are reasonably uncommon. The foundation that is most readily useful appears to be Minas Gerais, Brazil.
| Chemical Formula: | Na[AlSi3O8] |
| Sodium Aluminum Silicate | |
| Molecular Weight: | 263.02 gm |
| Composition: | Soldium | 8.30 % | Na | 11.19 % | Na2O |
| Calcium | 0.76 % | Ca | 1.07 % | CaO | |
| Aluminum | 10.77 % | Al | 20.35 % | Al2O3 | |
| Silicon | 31.50 % | Si | 67.39 % | SiO2 | |
| Oxygen | 48.66 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Triclinic – Pinacoidal |
| Crystal Habit: | (Albite) Crystals commonly tabular || {010}, may be curved, to 3 cm; divergent aggregates, granular, cleavable massive. |
| Twinning: | (Albite) Common around [010] or {010}, giving polysynthetic striae on {001} or {010}; many other laws, contact, simple and multiple. |
| Cleavage: | Perfect on {001}, very good on {010}, imperfect on {110} |
| Fracture: | Irregular/Uneven to Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 6.0 – 6.5 |
| Density: | 2.60 – 2.65 (g/cm3) |
| Luminescence: | Fluorescent, Short UV=cherry-red blue, Long UV=white. |
| Radioactivity: | Not Radioactive |
| Other: | F |
