Aragonite is a carbonate mineral, one of
the two common, naturally occurring, crystal
forms of calcium carbonate, CaCO3 (the other
form being themineral calcite). It is formed by biological and
physical processes, including precipitation from marine and
freshwater environments.
Aragonite\'s crystal lattice differs from that of
calcite, resulting in a different crystal shape,
an orthorhombic system with acicular crystals.
Repeatedtwinning results in pseudo-hexagonal forms. Aragonite
may be columnar or fibrous, occasionally in
branching stalactitic forms
called flos-ferri("flowers of iron") from their
association with the ores at
the Carinthian iron mines.
