Aragonite Crystal Raw Minerals Stones Rocks Collecting

Description

Origin : Morocco

Aragonite Crystals 10-30 gr - cm 2-4 Raw Minerals Stones Rocks for Collection, only a piece, ad in photo.
Also available in larger sizes, in plexiglas box, at this link.

Aragonite is a mineral made up of neutral calcium carbonate (CaCO3). It crystallizes in the bipyramidal rhombic class, it is a higher density polymorph of calcite and the crystal habitus is generally prismatic according to the vertical prism. Often the crystals are grouped in clusters of three or more individuals with a hexagonal pseudo-symmetry. However, very thin acicular, fasciculate or rayed crystals are also found. Fibrous, fibrous-rayed, stalactitic, pisolitic crystals are also found. They are also found in lamellar, columnar, coralloid or earthy aggregates.
Aragonite of inorganic origin generally occurs in thin and elongated crystals, gathered in tufts above all within fractures, microfractures, porosities, diaclases and cavities of chalky rocks (gypsum, CaSO4+2H2O) or limestone. Aragonite can be colorless or white, yellow, pink, purple, gray, blue, brown, reddish-brown, or green, and ranges from transparent to translucent with a luster that changes from vitreous to resinous. Aragonite is found in a sedimentary environment, it is the main constituent mineral, or in combination with others, of the hard parts of many marine organisms such as, for example, shells of molluscs and their pearls, the skeleton of cnidarians such as madrepores and others. They can also form in fumarolic deposits and in volcanic cavities.
The gray or reddish triple pseudo-hexagonal twins found in Molina de Aragón (Spain) are famous. Beautiful crystals come from Bastennes and the Clamouse Cave (France), from Horschenz and Podrecany (Bohemia) and from Sicily (Agrigento). Furthermore, aragonite is reported in the Alpine lithoclases of numerous Italian localities (Val Malenco, Cogne, Monte Ramazzo) and in the lavas of Monte Somma (Naples) and Etna. There are also deposits in the United States, Mexico, Morocco (from the latter lately massive quantities have been exported), Namibia, England, Scotland, Austria, Germany.
Discovered by the mineralogist and father of historical geology Abraham Gottlob Werner in 1797, this mineral owes its name to the Spanish region of Aragon. In reality, the first classified sample came precisely from Molina de Aragón, in the current Province of Guadalajara.
It reacts easily to acid attack, is strongly birefringent, is fluorescent and phosphorescent. Widely used in the building industry for the production of cements, it is also used today for the production of ornamental objects; the most aesthetically beautiful specimens are in great demand among collectors. Tiny crystals of aragonite are contained in the human body in the inner ear (otoliths of the vestibular system). Aragonite is also involved in the dolomitization process.