Geology Home Page
Roger Weller, geology instructor
Chemical Group: carbonates
Chemical Formula: CaMg(CO3)2
Color: colorless, white, gray, greenish, pink, yellowish brown
Luster: vitreous to pearly
Transparency: transparent to translucent
Hardness: 3.5 to
Specific Gravity: 2.85
Cleavage: rhombohedral, 3 directions Fracture: sub-conchoidal
Crystal Forms and
Habits: Trigonal system
Crystals are commonly rhombohedrons.
Saddle-shaped curved crystals are common.
Often in massive form, similar to limestone.
Mineral Associations: Specimens from the Tri-State district often have
chalcopyrite crystals with the dolomite.
Identifying Characteristics: Closely resembles calcite but reacts slower with
the application of cold dilute hydrochloric acid than calcite.
Uses: In pill form as a calcium source
Also used for a building and ornamental stone
Occurrences: Tri-State district, and Penfield Quarry, New York
Toxicity: when-swallowed- low when inhaled- moderate