from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A green radioactive mineral that is a hydrous crystalline phosphate of uranium and copper.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A radioactive green phosphate mineral, isostructural with autunite, found in granites and other uranium-bearing deposits as a secondary mineral.
from the GNU version of the Collaborative International Dictionary of English
- n. A mineral occurring in emerald-green tabular crystals having a micaceous structure. It is a hydrous phosphate of uranium and copper. Called also copper uranite, and chalcolite.
from The Century Dictionary and Cyclopedia
- n. A native phosphate of uranium and copper, occurring in square tabular crystals of a bright-green color, pearly luster, and micaceous cleavage. Also called chalcolite, and copper uranite.
The mica does not everywhere present this coarsely crystalline appearance, but in flexures and lines of union with the quartz and orthoclase is degraded to a mica schist upon whose surfaces appear uranates of lime and copper (autunite and torbernite), and in which are inclosed garnet crystals of considerable size and beauty.
AUTUNITE, or CALCO-URANITE, a mineral which is one of the "uranium micas," differing from the more commonly occurring torbernite (_q. v._) or cupro-uranite in containing calcium in place of copper.
The colour is sulphur-yellow, and this enables the mineral to be distinguished at a glance from the emerald-green torbernite.
Though closely resembling the tetragonal torbernite in form, it crystallizes in the orthorhombic system and is optically biaxial.
The radium-bearing minerals are torbernite and autunite (hydrous copper-uranium and calcium-uranium phosphates), and are found in dark felsite dikes near their intersections with east-west gold-silver-quartz veins.
; and as phosphate in the uranites, torbernite (hydrated phosphate of uranium and copper), and autunite (hydrated phosphate of uranium and lime).