Autunite
Meta-Autunite is a dehydration product of its cousin that is close. When the mineral Autunite loses water and converts to Meta-Autunite, it becomes what is known as a pseudomorph. A pseudomorph is generally speaking an atom by atom replacement of 1 mineral’s chemistry in position of another mineral’s chemistry, while the crystal that is initial outward shape remains mainly unchanged. The process actually leaves the crystal shape of the mineral that is original, nevertheless the original mineral is not any longer there. Pseudomorph translated from latin means shape that is falsepseudo=false; morph=shape). Meta-Autunite could be the more form that is stable of two and most specimens of Autunite are probably actually Meta-Autunite.
Meta-Autunite is just a mineral that is highly fluorescent. Uranium is the activator that is fluorescent Meta-Autunite and Autunite. Remember, because of the uranium, Meta-Autunite and Autunite are a radioactive minerals and must be stored away from other minerals that are influenced by radioactivity and exposure that is human being always be restricted. Autunite and Meta-Autunite are two associated with more attractive and radioactive that is popular.
Distribution of Autunite and Meta-Autunite is widespread, with many localities being minor but few for outstanding specimens. In France, at L’Ouche d’Jau, Saint-Symphorien-de-Marmagne, and the Les Oudots mine, Autun district, Saône-et-Loire; from the Margnac mine, Compreignac, Haute-Vienne; large crystals from the Gagnol mine, Lachaux, Puy-de-Dôme. From Sabugal, Urgeiri¸ca, and elsewhere in Portugal. At Peveragno, near Cúneo, Piedmont, Italy. Large crystals from Bergen, Vogtland, Germany. From the true number of localities in Cornwall, England. Fine groups from the mine, near Mt daybreak. Spokane, east of Elk, Spokane County, Washington, USA. At Malacacheta, Minas Gerais, Brazil. Large crystals from Mt. Painter, Flinders Ranges, South Australia.
| Chemical Formula: | Ca(UO2)2(PO4)2•6-8(H2O) |
| Hydrated Calcium Uranyl Phosphate | |
| Molecular Weight: | 986.26 gm |
| Composition: | Calcium | 4.06 % | Ca | 5.69 % | CaO |
| Uranium | 48.27 % | U | 54.76 % | UO2 | |
| Phosphorus | 6.28 % | P | 14.39 % | P2O5 | |
| Hydrogen | 2.45 % | H | 21.92 % | H2O | |
| Oxygen | 38.93 % | O |
| Crystallography: | Tetragonal – Ditetragonal Dipyramidal |
| Crystal Habit: | As thin to moderately thick crystals, tabular on {001} and with rectangular or octagonal outline, to 2 cm; commonly in subparallel growths, foliated or scaly aggregates, and in crusts. |
| Twinning: | On {110}, interpenetrant, rare. |
| Cleavage: | Perfect on {001}; Indistinct on {100} |
| Fracture: | Conchoidal to Irregular/Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | 2.0 – 2.5 |
| Density: | 3.05 – 3.20 (g/cm3) (varies with hydration) |
| Luminescence: | Fluorescent; Strong yellow-green in SW and LW UV |
| Radioactivity: | Very Strong; GRapi = 4,234,083.25 (Gamma Ray American Petroleum Institute Units) |
| Health Warning: | Contains uranium – always wash hands after handling. Avoid inhaling dust when handling or breaking. Never lick or ingest. Avoid prolonged exposure in proximity of the body. Store away from inhabited areas. |
| Other: | Dehydrates in air. Soluble in acids. Alters to Phosphuranylite. |
| Color: | Lemon-Yellow to sulfur-Yellow, Greenish Yellow to pale Green; may be dark Green to Greenish Black |
| Transparency: | Transparent to Translucent, Opaque |
| Luster: | Vitreous, Pearly on {001} |
| Refractive Index: | 1.584 – 1.607 Uniaxial ( – ), commonly anomalously Biaxial ( – ), dependent on the H2O content of the crystals. |
| Birefringence: | 0.023 |
| Dispersion: | Strong; r > v |
| Pleochroism: | Visible. X = colorless to pale yellow; Y = Z = yellow to dark yellow |
