Aragonite

Aragonite is a <a href="/facts/Carbonate_mineral/8DUmuAhp">carbonate mineral</a> and one of the three most common naturally occurring <a href="/facts/Polymorphism_(materials_science)/bu2tqsB9">crystal forms</a> of <a href="/facts/Calcium_carbonate/UQ1wLFna">calcium carbonate</a> (<a href="/facts/Calcium/hf252CC0">Ca</a><a href="/facts/Carbonate/FES1QHkN">CO3</a>), the others being <a href="/facts/Calcite/gKMHYQJo">calcite</a> and <a href="/facts/Vaterite/Hvgq1Kjz">vaterite</a>. It is formed by <a href="/facts/Biophysics/l9u5gqCy">biological and physical</a> processes, including <a href="/facts/Precipitation_(chemistry)/s3BgsLLY">precipitation</a> from <a href="/facts/Marine_ecosystem/thPh931d">marine</a> and <a href="/facts/Freshwater_ecosystem/G5xqs19j">freshwater</a> environments.

The <a href="/facts/Crystal_lattice/7gQKTsXk">crystal lattice</a> of aragonite differs from that of calcite, resulting in a different crystal shape, an <a href="/facts/Orthorhombic_crystal_system/3zo4F8P0">orthorhombic crystal system</a> with <a href="/facts/Acicular_(crystal_habit)/PGMnp4TX">acicular crystal</a>. Repeated <a href="/facts/Crystal_twinning/7xU6CKfR">twinning</a> results in pseudo-hexagonal forms. Aragonite may be columnar or fibrous, occasionally in branching <a href="/facts/Helictite/IKHjzT8v">helictitic</a> forms called flos-ferri ("flowers of iron") from their association with the <a href="/facts/Ore/kgc9DssX">ores</a> at the <a href="/facts/Duchy_of_Carinthia/DAWeLaGR">Carinthian</a> iron mines.

Aragonite open-in-new

Aragonite