Chemistry Reference Libraries

Page 7 of about 102 Articles
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....

2005-05-26 12:02:30

Cadmium is a chemical element in the periodic table that has the symbol Cd and atomic number 48. A relatively rare, soft, bluish-white, toxic transition metal, cadmium occurs with zinc ores and is used largely in batteries. Notable characteristics Cadmium is a soft, malleable, ductile, bluish-white bivalent metal which can be easily cut with a knife. It is similar in many respects to zinc...

2005-05-26 11:59:32

he mineral calcite is a calcium carbonate corresponding to the formula CaCO3 and is one of the most widely distributed minerals on the Earth's surface. It is a common constituent of sedimentary rocks, limestone in particular. It is also the primary mineral in metamorphic marble. It also occurs as a vein mineral in deposits from hot springs, and also occurs in caverns as stalactites and...

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,...

2005-05-26 11:56:59

Celestite (SrSO4) is a mineral consisting of strontium sulfate. The mineral is also known as celestine and is named for its occasional delicate blue color. Celestite occurs as crystals, and also in compact massive and fibrous forms. It is mostly found in sedimentary rocks, often associated with the minerals gypsum, anhydrite, and halite. The mineral is found worldwide, usually in small...

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...

2005-05-26 11:31:44

Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has chemical composition CuFeS2. It has a brassy to golden yellow color and hardness of 3.5 to 4 on the Mohs scale. Due to its color it is often confused with pyrite though this mineral has a cubic and not a tetragonal crystal system and chalcopyrite is more often massive and less brittle. Chalcopyrite...

2005-05-26 11:28:30

The term Chlorite can refer to the following meanings: - The chlorite group of clay minerals. - A Chlorite ion is a polyatomic anion consisting of an atom of chlorine and two oxygen atoms. Its chemical formula is ClO2-. The oxidation state of the chlorine atom within the chlorite ion is +3. How does the chlorite anion fit within the overall scheme of chlorine based anions? In general,...

Chromite Iron Chromium Oxide
2005-05-26 11:26:59

Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. Magnesium is always present in variable amounts, also aluminium and iron substitute for chromium. Chromite is found in peridotite and other layered ultramafic intrusive rocks and also found in metamorphic rocks such as serpentinites. Ore deposites of chromite form as early magmatic...

2005-05-26 11:26:21

Cinnabar (German Zinnober), sometimes written cinnabarite, is a name applied to red mercury(II) sulfide (HgS), or native vermilion, the common ore of mercury. The name comes from the Greek, used by Theophrastus, and was probably applied to several distinct substances. Other sources say the word comes from the Persian zinjifrah, originally meaning "lost". Cinnabar was mined by the Roman...

Word of the Day
  • A person in a secondary role, specifically the second most important character (after the protagonist).
The word 'deuteragonist' comes from a Greek word meaning 'an actor of second-class parts'.