a massive variety of uraninite, occurring in black pitchlike masses: a major ore of uranium and radium.
a blackish mineral that is a type of uraninite and occurs in veins, frequently associated with silver: the principal source of uranium and radium. Formula: UO2
also pitch-blende, 1770, a loan-translation of German Pechblende; see pitch (n.2) + blende.
A brown to black, often crusty, cubic mineral that is a principal ore of uranium. It is highly radioactive. Chemical formula: UO2.
noun, Machinery. 1. .
noun, Masonry. 1. a broad-edged chisel for cutting plane surfaces on stones.
noun, Machinery. 1. an imaginary circle within the profiles of the teeth of a gear, such that it rotates against a similar circle rotating at the same rate on a meshing gear. noun 1. an imaginary circle passing through the teeth of a gearwheel, concentric with the gearwheel, and having a radius that would enable […]
noun, Machinery. 1. See under . noun 1. (in a gear or rack) an imaginary surface forming a plane (pitch plane) a cylinder (pitch cylinder) or a cone or frustrum (pitch cone) that moves tangentially to a similar surface in a meshing gear so that both surfaces travel at the same speed.