• Chemistry: Mg(UO2)2Si2O7 - 6H2O, Hydrated Magnesium Uranyl Silicate.
  • Class: Silicates
  • Subclass: Nesosilicates
  • Uses: mineral specimen and very minor ore of uranium
  • Specimens

Sklodowskite is a rare uranium mineral that forms from the oxidation of uranium-bearing minerals. Found in good crystals only at one mine at the world famous copper and uranium locality of Shaba, Zaire, the Musonoi Mine produces some of the finest sklodowskite specimens. The mineral is named for the famous chemist Marie Sklodowska Curie, who discovered the element Radium. Its green-yellow to yellow velvety tufts are attractive and make for an unusual mineral specimen. Although less brilliantly colored than its cousins cuprosklodowskite and uranophane, sklodowskite is still much sought after by rare mineral collectors. Remember, this is a radioactive mineral and should be stored away from other minerals that are affected by radioactivity and human exposure should be limited.


  • Color is green-yellow to yellow.
  • Luster is vitreous to silky.
  • Transparency: Crystals are transparent to translucent.
  • Crystal System: Monoclinic
  • Crystal Habits are typically fibrous tufts and crusts. Also acicular crystals in radial aggregates.
  • Cleavage: perfect in one direction.
  • Hardness is 2 - 3.
  • Specific Gravity is approximately 3.5+ (above average for translucent minerals)
  • Streak is pale yellow.
  • Associated Minerals are uraninite, cuprosklodowskite and Uranophane.
  • Other Characteristics: Radioactive and fluorescent.
  • Notable Occurrences include Musonoi Mine, Shaba, Zaire and Crook Co., Wyoming, USA.
  • Best Field Indicators are crystal habit, color, locality, radioactivity and fluorescence.
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SKLODOWSKITE specimen skl-1
$ 125.00
Dims: 3-3/4" x 2-1/8" x 2-3/8"
Wt: 5.5 oz
Santa Eulalia, Chihuahua, Mexico
Several thin clusters of finely fibrous sklodowskite crystals are randomly scattered about this specimen. The crystals are at most 1/4 inch long, and about twice as thin as a human hair in thickness. These bright yellow radiating fibers rest on a host of surprisingly well-formed selenite crystals that almost attain a "ram's horn" form in one area. There is a very sparse amount of this rare mineral on this specimen, but given just how difficult it is to get ahold of, it's worth the money.
no photo
skl-1 ($125.00)
Santa Eulalia, Chihuahua, Mexico
SKLODOWSKITE specimen skl-2
$ 50.00
Dims: 2.3" x 1.5" x 1.5" (5.8 x 3.8 x 3.8 cm)
Wt: 3.69 oz. (104.6 g)
Musonie Mine, Zaire
The Sklodowskite needles on this specimen are locked into a rather interesting formation. The cuprite-laden host rock contains a hollow inside of which the Sklodowskite needles eventually formed, creating a crust that coated its surface. Then a copper-bearing mineral that could be either cuprosklodowskite or possibly torbernite filled in the rest of the hollow. This specimen shows part of the hollow that has been broken open to reveal the yellow Sklodowskite needles penetrating partway into the green "core". There are two smaller formations like this one on opposite sides of the larger formation. The visible Sklodowskite crystals do not exceed 0.3" (8 mm) in length or 1 mm in diameter, and have the standard yellow color and a dull pearly luster. It is impossible to determine their translucence, though I doubt that they would be transparent. Close examination makes me think that maybe all of the material started out as Sklodowskite and then underwent partial pseudomorphing, or maybe the material started out as the copper-based mineral, and so vice-versa. The host rock in which these formations rest appears to be made of a variety of different minerals, but the most prominent and easily definable of these is cuprite. Its dark gray color and dull metallic luster are easy to see, though it shows no evidence of crystal form. I really wish I knew what that copper-based mineral is!
no photo
skl-2 ($ 50.00)
Musonie Mine, Zaire
SKLODOWSKITE specimen skl-3
$ 40.00
Dims: 2.80x2.31x1.37" (7.12x5.87x3.48cm)
Wt: 5.73oz (162.1g)
Kamoto-Fond Mine, Kolwezi, Congo
This specimen displays at least three uranium minerals as visible distinct crystals. All of these crystals are in a circular 2-cm cavity at one end of the specimen. Most of the crystals are sklowdowskite, with golden-yellow crystals which are mostly translucent but some do appear transparent. Most of these also have a dull luster. Second most common are bright green crystals of cuprosklowdowskite, and least common are bright yellow transparent crystals of uranophane (these have a silky luster). The host rock also has a thin crust of a green mineral, and a loupe reveals that it is likely more cuprosklowdowskite, and is accompanied by additional crusts of sklowdowskite and even some uranophane.
no photo
skl-3 ($ 40.00)
Kamoto-Fond Mine, Kolwezi, Congo


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