Taxonomy term

usgs

Mineral Resource of the Month: Chromium

Although chromium is a metal, it does not occur naturally in metallic form. Chromium can be found in many minerals, but the only economically significant chromium-bearing mineral is chromite. Chromite has been mined from four different deposit types: stratiform chromite, podiform chromite, placer chromite, and laterite deposits. Most of the world’s resources, however, are located in stratiform chromite deposits, such as the Bushveld Complex in South Africa. The economic potential of chromite resources depends on the thickness and continuity of the deposit and on the grade of the ore. Many of the major stratiform chromite deposits also contain economic levels of platinum, palladium, rhodium, osmium, iridium and ruthenium.

13 Jun 2018

Mineral Resource of the Month: Titanium

Titanium is the ninth-most abundant element in Earth’s crust and is found in nearly all rocks and sediments, although it is not found as a pure metal in nature. It has a strong affinity for oxygen, typically forming oxide minerals — the most important being ilmenite and rutile. Processing of ilmenite and rutile in shoreline (beach) and fluvial (river and stream) heavy mineral sand deposits — found along many continental margins — provides most of the world’s titanium supply. Most of the remaining supply comes from two large hard rock deposits that contain ilmenite.

 
05 Feb 2018

Mineral Resource of the Month: Zinc

Zinc is a ubiquitous element occurring in many rocks in Earth’s crust and as a trace constituent in the oceans and the atmosphere. Zinc is commonly found in mineral deposits along with other base metals, such as copper and lead, and is produced mainly from three types of deposits: sedimentary exhalative, Mississippi Valley type, and volcanogenic massive sulfide. Sphalerite, a zinc sulfide mineral, is the primary ore mineral for zinc and has been the source for most of the world’s production.

 

04 Dec 2017

Troubled waters: Lead lurking in U.S. water supplies

In 2014, Flint, Mich., started drawing its drinking water from the highly corrosive Flint River, which leached lead from old pipes, exposing the population to lead poisoning. Such aging infrastructure exists in towns across the nation, leaving many to wonder if what happened in Flint could happen to them. The answer in many cases is yes.
30 Oct 2017

Mineral Resource of the Month: Strontium

Two strontium-bearing minerals, celestite (strontium sulfate, SrSO4) and strontianite (strontium carbonate, SrCO3), contain strontium in sufficient quantities to make recovery practical. Celestite occurs much more frequently and is the primary source of the world’s supply of strontium. Celestite occurs as crystals and as massive or fibrous aggregates in sedimentary rocks. It often displays a delicate blue color owing to the presence of impurities. Celestite can occur in bedded evaporite deposits in conjunction with gypsum, anhydrite and halite. It can also occur in cavities within carbonate rocks where it is precipitated from strontium-bearing groundwaters or brines.

 
02 Oct 2017

Mineral Resource of the Month: Silicon

Almost 30 percent of Earth’s crust consists of silicon, the second-most abundant element on Earth following oxygen. Silicon is rarely found free in nature; it combines with oxygen and other elements to form silicate minerals. These silicate minerals compose more than 90 percent of Earth’s crust. Silicates are the largest class of rock-forming minerals on Earth. Silicon dioxide, or silica, typically takes the form of quartz, the most common component of sand. Silicon is also the seventh-most abundant element in the universe.

07 Aug 2017

Mineral Resource of the Month: Fluorspar

Fluorspar, or fluorite, occurs in a variety of geological environments and is deposited under a wide range of chemical and physical conditions, but commercial sources are primarily hydrothermal. The most common deposits occur as veins, mantos (replacement strata-bound orebodies) or replacement deposits. Other important deposits include stockworks and fillings in shattered zones, carbonatite and alkalic rock complexes, residual concentrations resulting from the weathering of primary deposits, and recoverable gangue in base metal deposits.

07 Jun 2017

Mineral Resource of the Month: Fluorspar

Fluorite occurs in a variety of geological environments deposited under a wide range of chemical and physical conditions, but commercial sources are primarily hydrothermal. The most common deposits occur as veins, mantos (replacement strata-bound orebodies), or replacement deposits. Other important deposits include stockworks and fillings in shattered zones, carbonatite and alkalic rock complexes, residual concentrations resulting from the weathering of primary deposits, and recoverable gangue in base metal deposits.
25 May 2017

Mineral Resource of the Month: Iron and Steel Slag

Iron and steel slag, also known as ferrous slag, is produced by adding limestone (or dolomite), lime and silica sand to blast furnaces and steel furnaces to strip impurities from iron ore, scrap and other ferrous feed materials and to lower the heat requirements of the iron- and steelmaking processes. Ferrous slag forms as a dominantly calcium silicate melt that floats on top of the molten crude iron or steel; the slag is then removed from the liquid metal.
 
01 Jan 2016

Energy Notes: June 2014 - 2015

Oil and petroleum imports data are preliminary numbers taken from the American Petroleum Institute’s Monthly Statistical Report. For more information visit www.api.org.

01 Jan 2016

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