Gemstone Glossary

Dolomite

Well known for its typical beautiful pink color and pearly luster, Dolomite is named after a French mineralogist, and geologist, Deodat de Dolomieu (1750-1801). Dolomite is also found in a variety of color shades like white, yellow, gray, brown or black . The darker shade vaieties occur when iron is present in its crystals.

Dolomite is the most common member of the Dolomite group of minerals which includes Ankerite, Bensonite, Huntite, Kutnohorite, Minrecordite and Norsethite. Ankerite is the only other somewhat common member however it is much more scarce than Dolomite. The other members are considered rare to very rare.


Dolomite is a common sedimentary rock-forming mineral that can occur in massive beds several hundred feet thick. It is formed from Calcium Magnesium Carbonate (CaMg (CO3) 2). Thus, is used in some cement as a source of magnesium. Its hardness ranks 3.5-4 on the Moh’s Scale, with an average Specific Gravity of 2.86. Dolomite occurrences have been reported in many localities throughout the world but is most well known from sites in Midwestern quarries of the USA; Ontario, Canada; Pamplona, Spain; Switzerland; and in Mexico.

Dolomite crystals can be transparent to translucent, and pearly to vitreous in luster. The luster is unique and is probably the best illustration of a pearly luster. The pearl-like effect is best seen on the curved crystals as a sheen of light can sweep across the curved surface. It is the typical beautiful pink color, unique luster and unusual crystal habit that makes Dolomite a very attractive mineral specimen among collectors.