- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
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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 fibrous variety of chalcedony with fiber elongation perpendicular to the c crystallographic axis (opposite to normal chalcedony) and showing other optical anomalies.
Industry:Mining
A field name for a medium- to coarse-grained granoblastic metamorphic rock with little or no foliation or lineation.
Industry:Mining
A field term denoting the degree of luster of attrital coal as it compares to the brilliant luster of vitrain associated in the same locality. Compare: bright attritus.
Industry:Mining
A field term denoting, in accordance with an arbitrary scale established for use in describing banded coal, a frequency of occurrence of vitrain bands comprising 30% to 60% of the total coal layer. Compare: dominant vitrain; moderate vitrain; sparse vitrain.
Industry:Mining