- Industry: Mining
- Number of terms: 33118
- Number of blossaries: 0
- 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 ...
Mica with intergrowths of crystals or laminae resulting in books that split well in some places but tear to produce a large proportion of partial films.
Industry:Mining
Microcline with the most complete ordering possible of aluminum and silicon ions in the tetrahedral sites and the smallest angle for beta (maximum triclinicity). Compare: mesomicrocline
Industry:Mining
Microhardness determined from the resistance of metal to indentation by a pyramidal diamond indenter, having edge angles of 172 degrees 30' and 130 degrees , and making a rhombohedral impression with one long and one short diagonal. Compare: Mohs scale
Industry:Mining
Microite is found in many coals and occurs in large quantities in Gondwana coals and in Permocarboniferous coals of the former U.S.S.R. It is most abundant in coals with little exinite, or coals of high rank in which exinite cannot be recognized, and may occur in very persistent thick bands. It is present in small amounts in Carboniferous coals of the Northern Hemisphere.
Industry:Mining
Microscopic scratch developed on the polished surface of a rock or mineral as a result of abrasion.
Industry:Mining
Microscopically small, needlelike inclusions of rutile crystals in a natural gem, such as ruby, sapphire, or garnet, from which subsurface reflections produce a whitish sheen resembling that of silk fabric.
Industry:Mining
Mid. A system of working beds of clay ironstone in patches 10 to 30 yd (9.1 to 27.4 m) square and 18 to 20 ft (5.5 to 6.1 m) thick. The bottom beds are first worked out; then miners work the higher ones by standing upon the fallen debris. Compare: overhand stoping
Industry:Mining
Mid. An underground heading driven parallel to another, and used as the return air course.
Industry:Mining
