What is Aragonite?


Aragonite is a carbonate mineral, one of the two common, naturally occurring polymorphs of calcium carbonate. It’s primarily found in Spain, Morocco, and the United States. Aragonite is often used as a gemstone and is popular for its unique crystal formations and color variations.

Aragonite is a fascinating gemstone that comes in various colors, often including blues, browns, and whites. Its unique crystal formations make it a popular choice for collectors and for use in jewelry.

Gemstone Properties

Chemical ClassificationInorganic - Carbonate
ColorTypically white or colorless but can also be found in blues, browns, and yellows.
LusterVitreous to resinous.
TransparencyTransparent to translucent.
OccurrenceSpain (especially Aragon, from which it gets its name), Mexico, and Morocco.
FormationOften found in sedimentary and hydrothermal environments, including hot springs and caves.
DiaphaneityTransparent to translucent
Mohs Hardness3.5 to 4
Specific Gravity2.94
Diagnostic PropertiesTwinning in star-shaped groups.
Chemical CompositionCaCO3
PleochroismNot observed in aragonite.
Crystal SystemOrthorhombic
Optical PropertiesBiaxial (-)
Refractive Index1.529 - 1.685
Birefringence0.098 - 0.100
2V angleMeasured: 18°
DispersionNot typically noted for its dispersion.