Epididymite
Epididymite is a beryllium that is rare mineral that is situated in agpaitic pegmatite intrusions, an unusual igneous rock that has lots of alkaline metals such as sodium and poor in silica. These intrusions also have a great number of unusual elements such as for example beryllium, titanium, fluorine and planet that is rare but are usually low in aluminum and silica. Beryllium is a element that is somewhat exotic in unusual concentrations in agpaite pegmatites allowing Epididymite to form.
Epididymite is located in locations that are famous pegmatite that is agpaitic like Kola Peninsula, Russia; Mont Saint-Hilaire, Canada; Arø Island, Langesundfjord, Norway and Narssârssuk, Greenland. These are well known places for rare silicate minerals. Other Epididymite locations include Vevja quarry, Tvedalen, Norway; Vezná, Czech Republic; near Saint-Amable, Quebec, Canada; near Quincy, Norfolk County, Massachusetts, USA; and crystals which are large Mt. Malosa, Zomba region, Malayi.
| Chemical Formula: | NaBeSi3O7(OH) |
| Sodium Beryllium Silicate Hydroxide | |
| Molecular Weight: | 245.26 gm |
| Composition: | Sodium | 9.37 % | Na | 12.64 % | Na2O |
| Beryllium | 3.67 % | Be | 10.20 % | BeO | |
| Silicon | 34.35 % | Si | 73.49 % | SiO2 | |
| Hydrogen | 0.41 % | H | 3.67 % | H2O | |
| Oxygen | 52.19 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | As pseudohexagonal crystals, tabular on {001}, also elongated along [010], to 6 cm. Micaceous, spherulitic, fine to coarse granular, porcelaneous massive. |
| Twinning: | On {001}, common, simple and polysynthetic; also as trillings. |
| Cleavage: | Perfect on {001}, Distinct on {100} |
| Fracture: | Uneven to Conchoidal when massive |
| Tenacity: | Brittle |
| Moh’s Hardness: | 5.5 |
| Density: | 2.55 – 2.61 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Colorless, White, also tinted Violet, Blue, or Yellow when finely crystalline |
| Transparency: | Transparent to Translucent |
| Luster: | Vitreous on fractures, Pearly on cleavages |
| Refractive Index: | 1.536 – 1.546 Biaxial ( + ) or ( – ) |
| Birefringence: | 0.0020 |
| Dispersion: | Weak |
