Aragonite Vs. Calcite

Aragonite is a popular mineral composed of calcium carbonate.^[1] Calcite is a very popular mineral and its chemical composition is also calcium carbonate.^[2]

Quick Facts on Differences of Aragonite and Calcite

For a quick recap of the differences aragonite and calcite:

• While both aragonite and calcite can be hexagonal, in terms of crystallography, aragonite can be orthorhombic and calcite can be trigonal.
• While both aragonite and calcite can be vitreous, in terms of luster, aragonite can be dull or resinous and calcite can be pearly.
• Aragonite can be commonly green while calcite can be commonly red.
• Aragonite's rarity is more rare than calcite.
• Aragonite's hardness is higher than calcite - aragonite ranges from 3.5 to 4 and calcite is 3 on the Moh's scale.

Quick Facts on Similarities of Aragonite and Calcite

The similarities of aragonite and calcite include:

• Aragonite and calcite both can be opaque, translucent or transparent.
• For chemical formulas, aragonite and calcite both are CaCO3.
• Aragonite and calcite both streak white.
• Aragonite's specific gravity overlaps with calcite - aragonite ranges from 2.93 to 2.947 and calcite ranges from 2.71 to 2.94.

Summary of Aragonite

Aragonite is a mineral that is commonly found in sedimentary rocks such as limestone, dolomite, and marble. It is a polymorph of calcium carbonate, which means that it has the same chemical formula as calcite but a different crystal structure. Aragonite is named after the Aragon region in Spain where it was first discovered.

Summary of Calcite

Calcite is a mineral that is widely distributed throughout the world. It is a carbonate mineral that is composed of calcium carbonate, which gives it a white or colorless appearance. Calcite is often found in sedimentary rocks, such as limestone and marble, as well as in hydrothermal veins and in some metamorphic rocks. It is also found in the shells of marine organisms, such as clams and oysters.

Table Comparison of Aragonite vs Calcite