Gypsum Vs. Dolomite

Colors

• The color of dolomite ranges from gray, pink and white to colorless. The color of gypsum ranges from colorless to white.

Hardness

• The Moh's scale of hardness is a relative scale rated 1 to 10 and is used to judge the hardness of a mineral (10 being the hardest). On this scale, dolomite rates 3.5 to 4 while gypsum rates 2.

Source

• Common sources for gypsum in the U.S. include California, Ohio, Colorado, Michigan, Utah, and New Mexico. Worldwide, it's also found in Mexico, France and Switzerland. Dolomite is found in Canada, Switzerland, Spain, Mexico and throughout the U.S. Midwest.

Etymology

• Dolomite was named after French geoologist Deodat de Dolomieu (1750 to 1801). The name gypsum comes from the Greek word for plaster--"gupsos."

Crystal System

• Crystals are partly identified by their crystal system. The crystal system for dolomite is trigonal, while the system for gypsum is monoclinic.