Isometric

Isometric

Usually distinguished by its blue color, this mineral is found in nepheline syentites. It was discovered in 1811 in Greenland and was named to reflect its sodium content. Crystals are rare, it is commonly found massive, in embedded grains. This massive variety is often used as a decorative stone.

This is a group of minerals with the same structure. It commonly forms dodecahedrons with the color of the garnet varying with composition. For example, pyrope is red due to Ca and Fe; uvarovite is green due to the presence of calcium-chromium. Its name is derived from the Latin granatus, meaning “like a grain.”

This mineral can be recognized by its striking resinous luster and perfect cleavage. The red variety is called "ruby blende" or "ruby zinc," while the dark varieties are known as "black jack." It is the most important ore of zinc, which is used in galvanizing iron, making brass paint, wood preservative, and in dyes and medicine. The name comes from the Greek word meaning "treacherous," an allusion to the ease with which dark varieties were mistaken for galena, but yielded no lead.

Discovered in 1845 and named after its discovery locality in Skuterud Mines, Norway, this mineral forms in moderate to high temperature hydrothermal veins. It is an ore of cobalt and nickel. Cobalt is chiefly used in alloys for making permanent magnets and high-speed tool steel.

Nicknamed "Fool's Gold" for people frequently mistaking it for gold, pyrite is the most common sulfide mineral and is found in a wide variety of geological formations. It is often mined for the gold or copper associated with it and is a source of sulfur for sulfuric acid. The name is from a Greek word meaning "fire" for the sparks that flew from it when hit with another mineral or metal.

Discovered in 1856, this mineral was named after J. B. Pentland ( ) who discovered the mineral at Sudbury, Ontario. It is the principal ore of nickel, which is used chiefly in steel. Nickel is also an essential constituent of stainless steel. The mineral is usually found intergrown with pyrrhotite, from which it can be distinguished from because it is non-magnetic.

Easily recognized by it good cleavage, high specific gravity, softness, and lead-gray streak, this mineral is the primary ore mineral of lead. It is a very common sulfide that has been worked for its lead content as early as 3000 BC. The name is derived from the Latin galena, a name originally given to lead ore.

Part of the Tennantite-Tetrahedrite series, this mineral occurs in hydrothermal veins formed at low to moderate temperatures. It is an ore of copper and silver. The name is derived from the common tetrahedral form of its crystals.

Commonly found in hydrothermal veins formed at low to moderate temperatures, this mineral was named after Smithson Tennant (1761-1815), an English chemist. It was discovered in 1819 at Cornwall, England. It is part of the Tennantite-Tetrahedrite series.

Named from the Latin "spin", thorn, alluding to its sharp octahedral crystals, this mineral occurs as an accessory in basalts, peridotites, kimberlites, marbles, and pegmatites. When transparent and field-colored, it is used as a gem: ruby spinel or balls ruby.