Oxides

Oxides

  

This mineral is confined almost exclusively to the zinc deposits in Franklin, New Jersey. It is distinguished chiefly by its red color and orange-yellow streak. An ore of zinc, its name is in allusion to the high zinc content.

  

Discovered in 1772 in the Czech Republic, this mineral is named from its elemental composition containing uranium. It occurs in granitic and syenitic pegmatites, as colloform crusts in high temperature hydrothermal veins, and in quartz-pebble conglomerates. It is the chief ore of uranium.

  

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.

  

This mineral is characterized by its adamantine luster and red color. Its name is from the Latin rutilus meaning “reddish” and is one of the five forms of titanium dioxide found in nature. Its slender crystals can be found traversing quartz veins forming rutilated quartz. Most of the ore is produced as a coating of welding rods, but is also used to give a yellow color to porcelain and false teeth.

  

One of the most common manganese ore minerals, pyrolusite is used in making steel. It is widespread in its occurrence, forming in lacustrine, shallow marine, and bog deposits. It was named in 1827 from the Greek word for “fire” and “to wash” because it was used to remove brown and green tints in the making of glass.

  

Occurring as massive or botryoidal forms, this mineral is an ore of manganese. Its name is derived from two Greek words meaning “smooth” and “black” in allusion to its appearance.

  

Discovered in 1827 in Germany, this mineral was named in allusion to the manganese content, though it is a minor ore of manganese. It forms in low temperature hydrothermal or hot spring deposits and is found associated with other manganese oxides.

  

Strongly magnetic, this mineral is also known as “lodestone”. It is a common accessory mineral and can be found in banded iron formations. It is named for the locality Magnesia, Greece. A fable ascribes its name to a shepherd named Magnes, who first discovered the mineral on Mount Ida after noticing that the nails of his shoes and the iron ferrule of his staff adhered to the ground.

  

A common accessory mineral in igneous rocks, ilmenite was named after its type locality in the Ilmen Mountains in Russia. It is a major source of titanium, which is used principally in the manufacture of paint and as a structural material because of its high strength-to-weight ratio.

  

This mineral comes in many forms, both metallic and nonmetallic, such as: botryoidal (known as kidney ore), micaceous and foliated known as specular; and earthy, oolitic, iron roses. But regardless of its form, it can always be identified by its characteristic red streak. It is widely distributed and forms the most abundant and important ore of iron. The name is derived from a Greek word meaning “blood”, in allusion to the color of the powdered mineral.