- 行业: Mining
- Number of terms: 33118
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- Company Profile:
The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
A translucent pale to deep- or orange-red variety of chalcedony containing iron impurities. Compare: sard
Industry:Mining
A translucent, milk-white to green, yellow, or blue variety of common opal.
Industry:Mining
A transmission or gearset that provides drive to secondary drives, winches, etc.
Industry:Mining
A transparent colorless quartz containing closely packed, parallel fibers of crocidolite that impart to it a blue color. In form and sheen, it resembles tigereye to which it alters geologically. Differs from sapphire quartz, in which fibers are not parallel. Also spelled hawkeye. Compare: tiger's-eye
Industry:Mining
A transparent lighting device used as a main lighting device in mines. Its distribution characteristics are simple, since there is no control of light other than that provided by the interior of the upper part of the fitting, which absorbs a large proportion of the upward flux component from the lamp and reflects the remainder. It is usually to be found spaced at intervals of 20 to 50 ft (6.1 to 15.2 m), 6 to 7 ft (1.83 to 2.13 m) high, along the centerline of roads 12 to 14 ft (3.66 to 4.27 m) wide. In general, the most noticeable effect of such a layout is glare.
Industry:Mining
A transparent quartz crystal containing minute air-filled or liquid-filled internal cracks that produce iridescence by interference of light. The cracks may occur naturally or be caused artificially by heating and sudden cooling of the specimen.
Industry:Mining
A transparent quartz crystal containing minute air-filled or liquid-filled internal cracks that produce iridescence by interference of light. The cracks may occur naturally or be caused artificially by heating and sudden cooling of the specimen.
Industry:Mining
