Aragonite

Aragonite is a polymorph of the mineral calcite, both having the chemical composition CaCO₃. Its structure differs from calcite and leads to a different crystal shape, an orthorhombic system with acicular crystals. By repeated twinning pseudo-hexagonal forms result. It may be columnar or fibrous, occasionally in branching stalactitic forms called flos-ferri (flowers of iron) from their association with the ores at the Carthinian iron mines. The type location for aragonite is Molina de Aragón (Guadalajara, Spain), 25 km outside Aragon. Another famous aragonite cave is in Slovakia (The Ochtinska Aragonite Cave, see the external links). Aragonite (Calcium Carbonate) [1] File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Aragonite (Calcium Carbonate) [1] File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... In general, a polymorph is something that can exist in several states or forms. ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ... Calcite from Brushy Creek Mine, Missouri, USA. The mineral calcite is a calcium carbonate corresponding to the formula CaCO3 and is one of the most widely distributed minerals on the Earths surface. ... In crystallography, the orthorhombic crystal system is one of the 7 lattice point groups. ... Guadalajara is a province of central Spain, in the northern part of the autonomous community of Castile-La Mancha. ... Capital Zaragoza Area  â€“ Total  â€“ % of Spain Ranked 4th  47 719 km²  9,4% Population  â€“ Total (2003)  â€“ % of Spain  â€“ Density Ranked 11th  1 217 514  2,9%  25,51/km² Demonym  â€“ English  â€“ Spanish  Aragonese  aragonés Statute of Autonomy August 16, 1982 ISO 3166-2 AR Parliamentary representation  â€“ Congress seats  â€“ Senate...

Aragonite crystal from Aragon, Spain.

It exists naturally in the shells of chiton and other mollusks. The fossil shells of some extinct ammonites form a mineral called ammolite, which is primarily aragonite with impurities that make it iridescent and valuable as a gemstone. Photograph of an Aragonite crystal specimen from Aragon, Spain taken by Dlloyd. ... Photograph of an Aragonite crystal specimen from Aragon, Spain taken by Dlloyd. ... Families See text Chitons, also called polyplacophorans and rarely polyplacophores, are 860 species of molluscs of the Class Polyplacophora. ... Classes Caudofoveata Aplacophora Polyplacophora - Chitons Monoplacophora Bivalvia - Bivalves Scaphopoda - Tusk shells Gastropoda - Snails and Slugs Cephalopoda - Squids, Octopuses, etc. ... A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ... This article is about the marine animal. ... Ammolite is a very rare and precious opal-like organic gemstone found only along the eastern slopes of the United States and Canada. ... The iridescence of the Blue Morpho butterfly wings. ... A gemstone is a mineral, rock (as in lapis lazuli) or petrified material that when cut or faceted and polished is collectible or can be used in jewellery. ...

See also

• list of minerals
• Nacre - otherwise known as "Mother-of-Pearl"
• Pearl

Gem animals. ... A piece of nacre Nacre, also known as mother of pearl or sadaf, is an organic mixture of calcium carbonate (CaCO3) in the form of platy crystals of aragonite and conchiolin (a scleroprotein). ... For other things called pearl, see pearl (disambiguation). ...

External link

• Aragonite information
• The Ochtinska aragonite cave - Check the photogalery