aragonite

ara·go·nite

noun \ə-ˈra-gə-ˌnīt, ˈa-rə-gə-, ˈer-ə-\

Definition of ARAGONITE

: a mineral similar to calcite in consisting of calcium carbonate but differing from calcite in its orthorhombic crystallization, greater density, and less distinct cleavage

— ara·go·nit·ic \ə-ˌra-gə-ˈni-tik, ˌer-ə-gə-, ˌa-rə-\ adjective

Origin of ARAGONITE

German Aragonit, from Aragon, Spain

First Known Use: 1803

aragonite

noun    (Concise Encyclopedia)

A carbonate mineral, the stable form of calcium carbonate (CaCO) at high pressures. It is somewhat harder and has a slightly higher specific gravity than calcite. Aragonite is found in recent deposits formed at low temperatures near the surface of the earth, as in caves as stalactites, with ore minerals, in serpentine and other basic (see acid and basic rocks) rocks, and in sediments. Aragonite is the mineral normally found in pearls, and it occurs in some animal shells. It is polymorphous (same chemical formula but different crystal structure) with calcite and vaterite, and, with geologic time, changes to calcite even under normal conditions.