HISTORY, NAME, LOCALITIES: Mineralogists recognized aragonite, pronounced ah-RAG-uh-nite, as a mineral species in 1790, a time when it served as a white paint pigment. It is named for its type locality at Molina de Aragón, Spain. Collecting localities are found in Spain, Austria, the Czech Republic, Japan, Morocco, and the United States (Idaho, Arkansas, South Dakota).
MINERALOGY, PROPERTIES, OCCURRENCE: Aragonite [calcium carbonate, CaCO3] crystallizes in the orthorhombic system as short-to-long, usually twinned prisms with longitudinal striations. It has a Mohs hardness of 3.5-4.0, poor cleavage, and a specific gravity of 2.95. Aragonite occurs primarily in evaporite deposits of chemical sedimentary rocks, and also in regional metamorphic rocks and hydrothermal replacement deposits. It is translucent to transparent and usually white or colorless, however impurities impart a wide range of pastel colors. Aragonite and calcite are polymorphic forms of calcium carbonate.
METAPHYSICAL PROPERTIES, LORE, USES: Metaphysical practitioners believe that aragonite enhances patience and responsibility, reduces stress and anger, channels energy to constructive ends, and balances emotions. Because aragonite is often part of the calcareous content of limestone and dolomite rock, it is an industrial source of calcium carbonate for use in plaster, cement, white pigments, and agricultural lime. Although too soft for use in jewelry, massive aragonite, often known as “Mexican onyx” and “oriental alabaster,” is carved into decorative objects such as bookends and figurines.
COLLECTORS’ INFORMATION: Collectors value aragonite for its well-developed hexagonal crystals that are usually twinned into pseudohexagonal forms.