Aragonite specimens.
Size: approx. 3-14 cm.
SET OF 23 UNITS
Aragonite is a mineral composed of calcium carbonate; it is notable for being a polymorph of calcite, meaning that it shares the same chemical composition but crystallises in a different crystal system, specifically the orthorhombic system. It usually forms in oxidation zones of iron deposits, in hot springs and in caves, where it can exhibit spectacular forms such as the coralloid, popularly known as ‘iron flower’ due to its branches resembling marine corals. This mineral is more unstable and soluble than calcite, making it highly sensitive to changes in temperature and humidity, and is the main component of pearls and the mother-of-pearl in the shells of many molluscs, where it is deposited in microscopic layers that give it its characteristic lustre. In its natural state for collecting, it usually appears in colours ranging from pure white to honey or reddish tones due to the presence of oxides, and is highly prized for its acicular formations and hexagonal twins, which give it a unique geometric appearance.
