Geology or Related Geological Terms +

A type of worm characterized by numerous appendage-bearing or leg-bearing body segments; ringed worm; segmented worm: An annelid is an invertebrate organism with a flat body that is divided into segments.

Earthworms and leeches are annelids of the Phylum "Anelida".

Not characterized by or associated with mountain building nor the process of mountain formation; especially, by the upward displacement of the Earth's crust: Jack read in the article about an an anorogenic phase in the towering high area that was not created by mountain-making upheaval.

An invertebrate ocean animal with a roundish hollow body: A coral or a sea anemone are both considered to be anthozoans.

Hard, lustrous coal containing a high percentage of fixed carbon and low percentage of volatile matter: Anthracite is generally formed by dynamic metamorphism, but it may be produced by contact metamorphism induced by igneous intrusion.

Anthracite is a hard, dense, shiny variety of coal, containing over 90 percent carbon and a low percentage of ash and impurities, which causes it to burn without flame, smoke, or odor.

Because of its purity, anthracite gives off relatively little sulfur dioxide when burned.

A reference to an anticline: Anticlinal strata are so bent that one portion (limb) slopes upward toward another oppositely inclined.

The upfold of strata resembling an arch or peaked roof: An anticline is an upfold of layered rocks in an archlike structure.

Places at opposite points on the globe: In class, Mrs. Smart asked the students what countries were the antipodes, of their own country of Canada, or the countries directly on the other side of the Earth,

A glassy, variously colored calcium phosphates: Apatite minerals are used as a source of phosphorous to be used in fertilizer, rarely as a gemstone, and as a mineral specimen.

A blue variety of the mineral beryl: An aquamarine is a semiprecious gemstone which is used in jewelry.

1. A group of islands, or an area of sea containing a cluster of islands: The islands of an archipelago are usually volcanic in origin, and they sometimes represent the tops of peaks in areas around continental margins flooded by the sea.
2. Etymology: from Italian arcipelago, "the Aegean Sea" (13th century), from Greek arkhipelagos, from arkhi-, "chief" + pelagos, "sea".

Any of several related minerals of fibrous structure that offer great heat resistance because of their nonflammability and poor conductivity: Commercial asbestos is generally either made from serpentine ("white" asbestos) or from sodium iron silicate ("blue" asbestos).

The fibers are woven together or bound by an inert material. Over time the fibers can work loose, and because they are small enough to float freely in the air and be inhaled.

Asbestos usage is now strictly controlled, exposure to its dust can cause cancer.

Mineral mixture containing semisolid brown or black bitumen, used in the construction industry: Asphalt is mixed with rock chips to form paving material, and the purer varieties are used for insulating material and for waterproofing masonry.

Asphalt can be produced artificially by the distillation of petroleum.

A soft layer of the upper mantle of the planet Earth under the lithosphere: The asthenosphere is a region in the upper mantle of the Earth's interior, characterized by low-density, semiplastic (or partially molten) rock material chemically similar to the overlying lithosphere.

The upper part of the asthenosphere is believed to be the zone upon which the great rigid and brittle lithospheric plates of the Earth's crust move around.

The asthenosphere is generally located between 45–155 miles (72–250 km) beneath the earth's surface, though under the oceans it is usually much nearer the surface and at mid-ocean ridges rises to within a few miles or kilometers of the ocean floor.

1. A most common mineral and one of the most common minerals on the face of the Earth: Calcite minerals consist of about four percent by weight of the Earth's crust, and is formed in many different geological environments.

Calcite minerals are used in cements and mortars, in the production of lime, and limestone is used in the steel industry, in the glass industry, as ornamental stone, in chemical and optical uses, and as mineral specimens.
2. Etymology: from Latin calx +? -ite. The name from "chalix", the Greek word for lime.

Native aluminum oxide, the hardest naturally occurring mineral known apart from diamond (corundum rates 9 on the Mohs scale of hardness). The corundum mineral is the second hardest natural mineral known to science

A lack of cleavage also increases the durability of the corundum mineral . Its crystals are barrel-shaped prisms of the trigonal system.

Its two varieties are sure to be on any list of gemstones. The red variety of corundum is known as ruby and all the other colors of corundum are known as sapphire.

Besides being used as gemstones, corundum minerals are also utilized as an abrasive.