Calcite Vs. Dolomite

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

Quick Facts on Differences of Calcite and Dolomite

For a quick recap of the differences calcite and dolomite:

• For chemical formulas, calcite is CaCO3 while dolomite is CaMg(CO3)2.
• Calcite can be commonly red while dolomite can be commonly brown, pink, tan or yellow.
• Calcite's hardness is lower than dolomite - calcite is 3 and dolomite ranges from 3.5 to 4 on the Moh's scale.
  • Calcite can be scratched by copper pennies (3.5) while dolomite can not be.

Quick Facts on Similarities of Calcite and Dolomite

The similarities of calcite and dolomite include:

• Calcite and dolomite both can be opaque, translucent or transparent.
• In terms of crystallography, calcite and dolomite both can be hexagonal or trigonal.
• In terms of luster, calcite and dolomite both can be pearly or vitreous.
• Calcite and dolomite both streak white.
• Calcite's rarity is similar to dolomite.
• Calcite's specific gravity overlaps with dolomite - calcite ranges from 2.71 to 2.94 and dolomite ranges from 2.85 to 2.93.

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.

Summary of Dolomite

Dolomite is a mineral that is composed of calcium magnesium carbonate (CaMg(CO3)2). It is commonly found in sedimentary rocks and can be identified by its white, pink, or gray color and its rhombohedral crystal structure. Dolomite is often found alongside other minerals such as calcite, quartz, and feldspar.

Table Comparison of Calcite vs Dolomite