|
Name |
Chemical Composition |
%U3O8 | Color | Luster | Hardness | Specific Gravity SG |
Characteristics & Occurrence |
| Pitchblende | Uranium oxide | 50-80 | Black (Grayish, Greenish) | Pitch like Earthy, Dull or Glassy | 5-6 | 6-9 | In Veins; often with Sulphides of Cobalt, Nickel,Silver, Bismuth or Yellow Secondary Uranium Minerals. Never Brownish or Reddish. |
| Uraninite | Uranium oxide | 65-85 | Black (Grayish, Greenish, Brownish) | Pitch like Dull or Glassy | 5-6 | 8-10 | Small Amounts in Pegmatites and in Veins Almost Never Brownish or Reddish. |
| Betafite (fresh) | Uranium Columbate | 15-27 | Black to Greenish-Brown | Glassy to Sub-Metallic | 4-5 | 4-5 | In Pegmatites; Less Commonly, in Placers. Commonly Altered to Brown and Yellow Green. |
| Euxenite | Rare Earth Titarium Columbate | 1-20 | Black to Brown “Liver Brown” | Glassy When Fresh | 5-7 | 4-6 | Nests or Pockets in Pegmatites. |
| Samarskite | Rare Earth Columbate | 9-18 | Black to Brown “Liver Brown” | Glassy When Fresh | 5-6 | 4-6 | Similar to Euxenite |
| Fergusonite (Fresh) | Rare Earth Columbate | 0-8 | Black to Brown “Liver Brown” | Glassy | 5-6 | 4-6 | In Pegmatites; Less Commonly, in Placers. Usually Externally Coated with Buff to Pinkish Clay-like Material. |
| Brannerite (Fresh) | Uranium Titanium oxide | 40 | Jet Black (Brownish, Greenish) | Brilliant | 4 | 4-5 | In Placers. Rare: Known to Occur in the United States only in Idaho. Alters to Yellowish-Brown. |
| Thucholite | Hydrocarbon | 2-8 | Jet Black | Brilliant | 3-4 | 2 | Coal-Like: Will Burn. Sometimes Replaces Original Uraninite. |
| Carnotite | Potassium Uranium Vanadate | 50-55 | Canary Yellow | Earthy or Pearly | 2-3 | 4+ | Scattered Irregular Lenses in Sandstone Beds. Frequently Associated With Fossil Logs or Bones. |
| Tyuyamunite | Calcium Uranium Vanadate | 48-55 | Greenish Yellow | Earthy or Pearly | 2-3 | 3-4 | Associated With Calcite Minerals. Similar to Carnotite. |
| Autunite | Calcium Uranium Phosphate | 60
|
Lemon/Yellow or Apple Green | Pearly | 2-3 | 3 | Mica-Like Crystals, Usually Small, Earthy. A Common Secondary Uranium Mineral |
| Pyrochlore-Micolite | Columbium Tantalum Oxide | 0-15 | Pale Yellow to Colorless and Others | Glassy or Resinous | 5-6 | 4-6 | In Pegmatites, Syenites, Some Limestones. Often Associated with Lithium or Fluorine Minerals Placers. |
| Uranophane | Calcium Uranium Silicate | 65 | Various Shades of Yellow | Pearly to Greasy | 2-3 | 4 | An alteration Product of Gummite, Pitchblende or Other Uranium Minerals. Commonly Associated With Other Secondary Uranium Minerals. |
| Gummite | Variable | 40-80 | Yellow to Orange and Variable | Dull, Waxy, Greasy | 2-5 | 4-6 | Commonly Associated With Pitchblende. An Alteration Product of Uranium Minerals. Chiefly Uranium Oxide, Water and Lead. |
| Schroeck-Ingerite | Carbonate and Sulphate Containing Uranium | 30 | Yellow to Greenish- Yellow | Pearly | 2-3 | 1-2 | Rounded Masses Distributed in Gypsum-Bearing Sandy Clay. |
| Meta-Torbernite Also Torbernite | Copper Uranium Phosphate | 60 | Various Shades of Green | Pearly | 2-3 | 3-4 | Mica-Like Square Crystals. With Other Uranium Minerals as Coatings on Many Types of Rocks. |
