Uranium dioxide, the primary ore of uranium, typically black and often massive ('Pitchblende'). It's extremely radioactive and associated with profound transformation and power. (Strictly a collector's mineral, not for metaphysical handling).
Black, Brownish-Black, Greyish, Greenish, often with a submetallic, pitchy, or greasy luster, forms cubic or octahedral crystals or massive
Uraninite is classified as a oxide minerals mineral which typically crystallizes in the isometric system. Its chemical formula is Uranium dioxide or uranium(IV) oxide (UO2). Common crystal habits include massive, botryoidal, granular. octahedral crystals uncommon..