APPLICATIONS: | Minor ore of uranium and mineral specimens. |
ASSOCIATED MINERALS: | Torbernite, meta-torbernite, uranocircite, uranophane, uraninite and other uranium minerals. |
CHEMICAL STRUCTURE: | Ca(UO2)2(PO4)2-10H2O, Hydrated Calcium Uranyl Phosphate. |
CLASS: | Phosphates. |
CLEAVAGE: | Perfect in one direction. |
COLOR: | Various shades of dark green to bright "lemon" yellow, often with a mixture of yellow and green shades in one specimen. |
CRYSTRAL HABITS: | Tabular square crystals dominated by two pinacoid faces. Crystals are often in parallel growths that can have a "fanned-out" look or in rosetta clusters. Also as crusts, earthy masses, foliated and scaly aggregates. |
CRYSTAL SYSTEM: | Tetragonal, 4/m 2/m 2/m. |
FIELD INDICATORS: | Color, crystal habit, fluorescence, radioactivity, associations and flexible crystals. |
FRACTURE: | Uneven. |
GENERAL INFORMATION: | Fluorescent yellow-green, radioactive, somewhat pleochroic and thin crystals or cleavage sheets are bendable. |
GEOGRAPHY: | Autun, France; Cornwall, England; Mitchell Co., North Carolina and Mt. Spokane, Washington, USA; Zaire; Bergen, Germany and Portugal. |
GROUP: | Autunite/Torbernite. |
HARDNESS: | 2 - 2.5. |
LUSTER: | Vitreous to pearly on the main pinacoid. |
TRANSPARENCY: | Translucent to opaque. |
SPECIFIC GRAVITY: | 3.1 - 3.2. |
STREAK: | Yellow. |
