quartz flour
1Rock flour — Rock flour, or glacial flour, consists of clay sized particles of rock, generated by glacial erosion or by artificial grinding to a similar size. Because the material is very small, it is suspended in river water making the water appear cloudy.… …
2Silicosis — Classification and external resources ICD 10 J62 ICD 9 502 …
3Geology of Tasmania — Tasmania has a varied geological history, with the world s biggest exposure of diabase, or dolerite. Rocks from the Neoproterozoic, Paleozoic and Mesozoic time periods appear. It is one of the few southern hemisphere areas glaciated during the… …
4List of California Historical Landmarks — This is a list of California Historical Landmarks. The official list may be seen [http://ohp.parks.ca.gov/listed resources/?view=all here] . NOTOC · =Alameda County= For more details, please see http://ohp.parks.ca.gov/default.asp?page id=21388.… …
5Sand casting — Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. It is relatively cheap and sufficiently refractory even for steel foundry use. A suitable bonding agent (usually clay)… …
6millstone — /mil stohn /, n. 1. either of a pair of circular stones between which grain or another substance is ground, as in a mill. 2. anything that grinds or crushes. 3. any heavy mental or emotional burden (often used in the phrase a millstone around one …
7sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… …
8Inventions in medieval Islam — A significant number of inventions were developed in the medieval Islamic world, a geopolitical region that has at various times extended from Al Andalus and Africa in the west to the Indian subcontinent and Malay Archipelago in the east.… …
9National Register of Historic Places listings in Flathead County, Montana — Location of Flathead County in Montana This is a list of the National Register of Historic Places listings in Flathead County, Montana. This is intended to be a complete list of the properties and districts on the National Register of Historic… …
10California Gold Rush — The California Gold Rush (1848 ndash;1855) began on January 24, 1848, when gold was discovered by James Marshall at Sutter s Mill in Coloma, California. [E] vents from January 1848 through December 1855 [are] generally acknowledged as the Gold… …
