Quantcast

Economic geology Reference Libraries

Page 1 of about 7 Articles
Bornite
2005-05-26 12:03:03

Bornite is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the cubic system. It has a brown to copper-red color on fresh surfaces that tarnishes to an iridescent purple surface. Its purple to bronze iridescence gives it the nickname peacock ore. Bornite is an important copper ore mineral and occurs widely in porphyry copper deposits along with more common chalcopyrite....

Cassiterite
2005-05-26 11:58:03

Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite is the chief ore of tin today. Most sources of cassiterite today are found in alluvial or placer deposits containing the resistant weathered grains. The best source of primary cassiterite is the tin mines of Bolivia,...

Chalcocite
2005-05-26 11:32:33

Chalcocite, copper(I) sulfide (Cu2S), is an important copper mineral ore. It is opaque, being colored dark-gray to black with a metallic luster. It has a hardness of 2½ - 3. It is a sulfide with an orthorhombic crystal system. Chalcocite is sometimes found as a primary vein mineral in hydrothermal veins. However, most chalcocite occurs in the supergene enriched environment below the...

Hematite
2005-05-26 10:41:56

Hematite (AE) or haematite (BE) is the mineral form of Iron (III) oxide, (Fe2O3), one of several iron oxides. The ore sometimes contains slight amounts of titanium. When shaped into ornaments, it is often called black diamond. Hematite is a very common mineral, coloured black to steel or silver-gray, brown to reddish brown, or red. It is mined as the main ore of iron. Varieties include...

Magnetite
2005-05-26 09:20:28

Magnetite is a magnetic mineral form of both iron(II) oxide and iron(III) oxide or (iron(II,III) oxide), with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. Magnetite is the most magnetic of all the minerals on Earth, and these magnetic properties led to lodestone being used as an early form of magnetic compass. Small grains of magnetite occur in...

Pentlandite
2005-05-26 08:33:21

Pentlandite is a iron-nickel sulfide, (Fe,Ni)9S8. Pentlandite usually has a Ni:Fe ratio of close to 1:1. It also contains minor cobalt. Pentlandite forms isometric crystals, but is normally found in massive granular aggregates. It is brittle with a hardness of 3.5 - 4 and specific gravity of 4.6 - 5.0 and is non-magnetic. It has a yellowish bronze color. Pentlandite is the chief ore of...

Tourmaline
2005-05-25 11:15:23

The mineral tourmaline is chemically one of the most complicated silicate minerals. It is a complex silicate of aluminium and boron but because of isomorphous replacement (solid solution) its composition varies widely with iron, magnesium and lithium and other elements entering into the combination to a greater or lesser extent. Tourmaline belongs to the trigonal crystal system and occurs as...

Word of the Day
lunula
  • A small crescent-shaped structure or marking, especially the white area at the base of a fingernail that resembles a half-moon.
This word is a diminutive of the Latin 'luna,' moon.
Related