Common Uranium Minerals Classified by Colors

Common Uranium Minerals Classified by Colors


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.