CaMg(CO3)2 - Calcium Magnesium Carbonate. Iron may substitute for some of the magnesium. Transparent to translucent crystals are typically colorless, white, gray or pink, but if iron impurities are present can be red, brown or even black. In massive form, dolomite is typically buff, gray, or white.

Dolomite is not naturally red; in its purest form, it is typically white, colorless, gray, or pink. However, dolomite can appear red due to impurities or environmental staining. The most common cause of red-colored dolomite is the presence of iron oxide (hematite) or other mineral inclusions that permeate the crystalline structure during formation. A famous example of this is the "Dolomite Alps" in Italy, where the mountains can take on a striking reddish or burnt-orange hue during sunset—a phenomenon known as the Enrosadira. This is caused by the light hitting the magnesium and calcium carbonate minerals. Additionally, some "Red Dolomite" is sold as a healing stone or decorative gravel, which is usually sedimentary dolomite that has been naturally stained by surrounding red clay or iron-rich soil. So, while the mineral itself isn't red, it is a geological "chameleon" that frequently takes on reddish tones based on its chemistry.