Publications

The estimated value of natural gemstones produced from U.S. deposits during 2012 was $11.1 million, a slight increase from 2011. U.S. gemstone production included agate, amber, beryl, coral, garnet, jade, jasper, opal, pearl, quartz, sapphire, shell, topaz, tourmaline, turquoise and many other gem materials.

World fluorspar demand slowed in 2012 and, according to some sources prices decreased, especially in the latter half of the year. In 2012, nearly all fluorspar (CaF2) consumption in the United States was from imports. Hastie Mining and Trucking Co. produced some fluorspar as a byproduct of its limestone quarry operations in Illinois. In addition, a small amount of usable synthetic...

Four companies mined fire clay in three states in 2012. Production, based on a preliminary survey of the fire clay industry, was estimated to be 230 kt (254,000 st) valued at $6.98 million, an increase from 215 kt (237,000 st) valued at $6.15 million in 2011. Missouri was the leading producing state, followed by Colorado and Texas, in decreasing order by quantity. The number of companies...

The United States continues to be the world’s leading producer and consumer of diatomite. Production of diatomite in the United States during 2012 was estimated to be 820 kt (903,000 st), a slight increase compared with 2011 production. The unit value of diatomite varied widely by end use in 2012. Diatomite used as a lightweight aggregate was priced at $11/t ($9.98/st), while specialty...

Common clay is a natural, fine-grained material composed of hydrous aluminum silicates. Shale is a laminated sedimentary rock formed by the consolidation of clay, mud and or silt.

The element bromine is found principally as a dissolved species in seawater, evaporitic (salt) lakes and underground brines associated with petroleum deposits. Seawater contains about 65 parts per million of bromine or an estimated 907 Gt (100 trillion st). In the Middle East, the highly saline waters of the Dead Sea are estimated to contain 907 Mt (1 billion st) of bromine. Bromine also...

Four minerals represent 90 percent of the borates used by industry worldwide — the sodium borates (tincal and kernite), calcium borate (colemanite) and the sodium-calcium borate (ulexite). Borax is a white crystalline substance, chemically known as sodium tetraborate decahydrate, and is found naturally as the mineral tincal. Boric acid is a colorless crystalline solid sold in technical...

The United States is reliant upon imports for nearly all of the bauxite that it consumes. Small amounts of bauxite and bauxitic clays are produced in Alabama, Arkansas and Georgia for nonmetallurgical uses. Metallurgical-grade bauxite (crude dry) imports in 2012 totaled 10.3 Mt (11.3 million st), 8 percent more than the quantity imported in 2011. Jamaica (46 percent), Guinea (27 percent)...

Barite is the mineralogical name for barium sulfate, which is also referred to as barytes. The most basic marketable product is known as “crude barite,” which is barite that usually has undergone simple beneficiation methods, such as jigging, tabling and washing, or more complex methods, such as flotation, heavy-media separation and magnetic separation. Most barite ore requires some...

Four companies — H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co. and Unimin Corp. — mined ball clay in five U.S. states in 2012. Production, on the basis of preliminary data, was 900 kt (992,000 st), with an estimated value of $42.3 million. This was a slight increase in tonnage from 886 kt (977,000 st), with a value of $40.9 million in 2011. Tennessee was the leading ball clay...

We examined the relative effectiveness of two innate immune responses in two species of New World blackbirds (Passeriformes, Icteridae) that differ in resistance to West Nile virus (WNV). We measured degranulation and oxidative burst, two fundamental components of phagocytosis, and we predicted that the functional effectiveness of these innate immune responses would correspond to the...

No abstract available.