What does uraninite mean?
Uraninite is a mineralogist's term for a black, often metallic and lustrous mineral composed principally of uranium dioxide (UO₂). It occurs in uranium-bearing rocks, particularly granite pegmatites, and can form through the alteration of other uranium minerals. Its importance is both practical and historical: uraninite is an important uranium ore and was central to early radioactivity research. The name “pitchblende” remains familiar for material historically described as uraninite, although the terms are not always interchangeable in modern usage, since pitchblende may also refer to altered or impure uranium material. In technical writing, uraninite usually denotes the specific crystalline mineral species rather than uranium ore in general. Outside geology and related scientific fields, the word is uncommon, so context matters: a general reader will usually encounter it in discussions of mineralogy, nuclear materials, mining, or the history of radioactivity.
nounA black, often metallic and lustrous mineral composed principally of uranium dioxide (UO₂), occurring as an important uranium ore and as an alteration product of other uranium minerals.
- A black, metallic to submetallic uranium mineral with the ideal composition uranium dioxide (UO₂), occurring in uranium-bearing rocks and formed also as an alteration product of other uranium minerals.
"The specimen displayed the dark, metallic lustre characteristic of uraninite."
"Mineralogists identified the black crystals as uraninite, an important uranium ore."
"The geologist found small grains of uraninite embedded in the granite specimen."
The plural is grammatically possible but uncommon; discussion usually focuses on a single mineral species or on uranium-bearing deposits.
"The catalogue describes several exceptional uraninites from famous uranium deposits."
Uraninite carries a celestial name into nuclear science: uranium was named for Uranus, and this mineral helped launch modern radioactivity research.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does uraninite come from?
Uraninite was formed in English in the early 19th century from uranium plus the mineral-forming suffix -ite. Uranium itself was named by Martin Heinrich Klaproth in 1789 after Uranus, the ancient sky god and namesake of the planet. Related forms such as uranic, uranyl, and uranate preserve the same uranium root.
How uraninite is actually used
A specialized term used chiefly in mineralogy, geology, nuclear-materials science, and the history of radioactivity. Outside those fields it is uncommon, and pitchblende remains the more familiar name for much historically discussed uranium mineral material.
Easily confused with uraninite
Pitchblende is a historical name for uraninite and may also refer more broadly to altered or impure uranium material, whereas uraninite specifically denotes the crystalline mineral uranium dioxide.