Aragonite bowl rectangular (100-150mm) completely hand cut! (Colors and drawings may vary)

Aragonite is a calcium carbonate with the chemical formula CaCO3. It is an unstable polymorph of calcite, making it difficult to distinguish from calcite because most of its properties are similar. A color test can help: with a Feigl solution, aragonite turns black, while calcite remains colorless. Aragonite is also slightly harder than calcite, which can be determined via a scratch test. A third method is the habit: aragonite usually grows in needle-shaped crystals (acicular), while calcite has a leaf-shaped habit. Powder diffraction can make the difference clear, because aragonite has an orthorhombic structure and calcite a trigonal one. Aragonite is formed at low temperatures close to the Earth's surface and occurs in geysers, hot springs, caves, as oolites in shallow seas, in shells and in pearls. Locations in Europe include Aragón (Spain), Limousis (France), Girgenti (Sicily), Bilin (Bohemia) and Eisenertz (Austria).