The product most frequently occurs as a massive finely to coarsely granular rock, grey, white or bluish in colour, resembling limestone. In metamorphic form it occurs as dolomitic marble. It crystallizes in small rhombohedral crystals often with curved faces, usually white, pink or yellow in colour.

Composition: Dolomite, calcium, magnesium carbonate also know as pearl spar and magnesium limestone (CaMgCO₃), contains theoretically CaO 30.4%; MgO 21.9%; CO2 47%; or 9CaO3 54% and MgCO 45.8%).

CaCO₃ .……………….72.02%

CaO……..………………..40.35%

MgO …..…………………13.05%

MgCO₃ .……………….27.25%

CaSO4 ……………………0.11%

Fe₂O₃ ……………………0.23%

AI₂O₃ ……………………0.08%

SiO₂ ……………………….0.26%

LOI …..……………………..43.10%

Mesh Size: 500# (25 microns)

Hardness: 3.5 – 4

Specific Gravity: 2.8 – 2.9

Melting Point: does not melt; 2700 to 3100⁰F is reduced to CaO + MgO

Index of refraction: When pure 1.500 to 1.681; iron content increases index

Colour: Snow White

Streak: White

Luster in crystals: vitreous or pearly in finely granular dull or earthy

Cleavage crystals: good rhombohedral

Fracture in massive form: rough to nearly conchoidal

Transparency: Translucent to opaque

Tenacity: rather brittle

Solubility: usually slight in cold, dilute acids, but good in hot acid.

As a flux in smelting iron, steel, ferro alloys and so on

In the manufacture of lime. Dolomite is used for high magnesium limes

Agriculture limestone

As crushed stone, rip rap and rubble

As building stone (use of dolomite limited except as dolomite marble)

In finely pulverized form as a substitute for chalk whiting, used in putty, paint, rubber and so on, dolomite used less than pure limestone, calcite or marble.

As terrazzo, stuccor dash, concrete block facings and so on.

The most important uses of dolomite for which limestone cannot be substituted are in the manufacture of dead-burned dolomite refractories and in the preparation of basic magnesium carbonate, which is used with asbestos in making”85% magnesia” heat insulating material. It has been in the manufacture of Epsom salts.