Chemistry Reference Libraries

Page 8 of about 102 Articles
2005-05-26 11:24:59

Coal is a fossil fuel extracted from the ground either by underground mining, open-pit mining or strip mining. It is a readily combustible black or brownish-black sedimentary rock. It is composed primarily of carbon and hydrocarbons, along with assorted other elements, including sulfur. Often associated with the Industrial Revolution, coal remains an enormously important fuel and is the most...

2005-05-26 09:41:33

The mineral kyanite is an aluminium silicate of the sillimanite group (along with andalusite and sillimanite), also called alumino-silicate. It has the formula Al2O3·SiO2 (Al2SiO5). Its hardness varies widely depending on its crystallographic direction, from 5 to 7.5, and it has a specific gravity of 3.56-3.67. It is translucent, usually blue, but possibly white, gray, green, or black. It...

2005-05-26 09:37:09

Limonite Limonite is a ferric hydrate of varying composition, the generic formula is frequently written as FeO(OH)·nH2O, although this is not entirely accurate as Limonite often contains a varying amount of oxide compared to hydroxide. Together with hematite, it is mined as ore for the production of iron. Limonite is heavy and yellowish-brown. It is not a true mineral, however, but a...

2005-05-26 09:33:48

Lithium is the chemical element with symbol Li and atomic number 3. In the periodic table, it is located in group 1, among the alkali metals. Lithium in its pure form is a soft, silver white metal, that tarnishes and oxidizes very rapidly in air and water. It is the lightest solid element and is primarily used in heat transfer alloys, in batteries and serves as a component in some drugs known...

2005-05-26 09:25:43

Magnesium is the chemical element in the periodic table that has the symbol Mg and atomic number 12. Magnesium is the eighth most abundant element and constitutes about 2% of the Earth's crust, and it is the third most plentiful element dissolved in seawater. This alkaline earth metal is primarily used as an alloying agent to make aluminium-magnesium alloys. Notable characteristics...

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...

2005-05-26 09:19:18

Malachite is a carbonate mineral, copper(II) carbonate hydroxide Cu2CO3(OH)2. Malachite has a hardness between 3.5 and 4. It crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagtitic masses. Malachite often results from weathering of copper ores and is often found together with azurite (Cu3(CO3)2(OH)2), goethite, and calcite. Except for the green...

Manganite Manganese oxide
2005-05-26 09:07:13

Manganese is a chemical element in the periodic table that has the symbol Mn and atomic number 25. Notable characteristics Manganese is a gray-white metal, resembling iron. It is a hard metal and is very brittle, fusible with difficulty, but easily oxidized. Manganese metal is ferromagnetic only after special treatment. The most common oxidation states of manganese are +2, +3, +4, +6...

Ore of Mercury
2005-05-26 08:49:14

Mercury (element) Mercury, also called quicksilver, is a chemical element in the periodic table that has the symbol Hg (from the Greek hydrargyrum, for watery (or liquid) silver) and atomic number 80. A heavy, silvery, transition metal, mercury is one of only two elements that are liquid at room temperature (the other is bromine). Mercury is used in thermometers, barometers and other...

2005-05-26 08:40:58

The mica group of minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic with a tendency towards pseudo-hexagonal crystals and are similar in chemical composition. The highly perfect cleavage, which is the most prominent characteristic of mica, is explained by the hexagonal sheet-like arrangement of its atoms. The word "mica" is thought...

Word of the Day
  • A volcanic mudflow.
The word 'lahar' comes from Javanese.