Eastern Mineral and Environmental Resources Science Center

Critical mineral - tungsten

A sample of pyrite and quartz. Iron pyrite, also known as Fool's Gold due to its resemblance to gold, often occurs in quartz veins. Pyrite is an important source of sulfur dioxide, which is primarily used to create sulfuric acid, an important industrial acid. In fact, consumption of sulfuric acid has been regarded as one of the best indexes of a nation's industrial

A sample of native gold. Gold has been treasured since ancient times for its beauty and permanence.   Most of the gold that is fabricated today goes into the manufacture of jewelry, but it also performs critical functions in computers, communications equipment, spacecraft, jet aircraft engines, and a host of other products. Read more about gold

This is a sample of rutile, one of the primary mineral sources of titanium. While as a metal, titanium is well known for corrosion resistance and for its high strength-to-weight ratio, approximately 95% of titanium is consumed in the form of titanium dioxide (TiO₂), a white pigment used in paints, paper, and plastics. Read more about titanium

A sample of augelite and quartz. Augelite is an aluminum phosphate mineral, primarily prized for collecting rather than as a source for its industrial mineral components.

Sample provided by Carlin Green, USGS. Sample originated from Mundo Nuevo Mine, Peru, and is 3.7cm in size.

This is a sample of axinite with iron, making it ferroaxinite. Axinite is primarily used as a collectors mineral.

Sample provided by Carlin Green, USGS. Sample originated from Puiva Mount, Russia, and is 3.0cm in size.

A sample of azurite, the blue mineral, and malachite, the green mineral. Both azurite and malachite are copper minerals that were once used as pigments but are now mostly valued as collectors minerals. They do serve as good indicators of copper deposits that can be developed. Read more information about copper here.

This sample is clinozoisite, a calcium aluminum silicate mineral. It is mostly prized as a collectors mineral rather than a source of its industrial mineral commodities.

Sample provided by Carlin Green, USGS. Sample originated from Hachupa, Pakistan, and is 6.0cm in size.

Elbaite is one of the best-known members of the tourmaline mineral family, particularly for its high-quality gemstones. Read more about the tourmaline mineral family here. 

Sample provided by Carlin Green, USGS. Sample originated from Himalaya Mine, California, and is 4

Epidote is a silicate mineral used mostly as a semiprecious gemstone.

Sample provided by Carlin Green, USGS. Sample originated from Prince of Wales Island, Alaska, and is 6.0cm in size.

Pyrrhotite is an iron sulfide mineral related to iron pyrite, which is one of the minerals known as Fool's Gold. Pyrrhotite, although not one of the Fool's Gold minerals, is sometimes called magnetic pyrite as it is weakly magnetic. It is most valued as a collectors mineral.

Sample provided by Carlin Green, USGS. Sample originated from Eagle Mine, Michigan, and is 4