Dolomite

Dolomite is a calcium carbonate mineral often used in construction as ballast, aggregate or hardcore – although it is also used as a source of Magnesia.

In mineralogical terms, Dolomite is sometimes used as a collectors specimen – variations with Cobalt make beautiful mineral specimens.

Appearance

Dolomite occurs in many forms and is a very common mineral, so describing it can be a little tricky – some specimens are fine crystals, some are simply grainy masses.

Uses and History

Dolomite is typically used as an ornamental stone, an aggregate, or a source of magnesia and magnesium oxides. It is used for smelting and glass making processes. It can be used in gardening to alter the pH of soils.

Dolomite was probably first discovered in 1768 by Carl Linnaeus. It was named after the French geologist Dolomieu who first described it as a mineral.

Mineralogy

Chemistry
Calcium magnesium carbonate mineral with the formula CaMg(CO3)2.
Colours and Variations

Often white, grey, brown, reddish, colourless.

There are several interesting varieties, including:

  • Cuprian dolomite (copper bearing)
  • Cobaltoan dolomite (bright pink, cobalt bearing)
  • Manganoan dolomite (Manganese bearing, pink)
  • Ferroan dolomite (iron bearing)
Streak
White
Luster
Vitreous to pearly
Fracture
Conchoidal
Transparency
Can be transparent, translucent, or opaque.
Crystal system
Trigonal – rhombohedral
Crystal habit
Tabular crystals, columnar, stalactitic, granular, grainy, massive.
Mohs hardness
3.5-4.0
Specific Gravity
2.8-2.9
Easiest testing method
Weak reaction to dilute acid, rhombohedral cleavage
Common associations
Quartz, Calcite, Pyrite, Sphalerite, Chalcopyrite, Fluorite, Galena, Baryte

Hazards and Warnings

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis. When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Locales

Dolomite occurs in most countries worldwide, and is one of the more common minerals found on Earth.

Translations

Arabic:

  • الدولوميت

Hindi:

  • डोलोमाइट

Portuguese:

  • dolomita

Bengali:

  • ডলোমাইট

Indonesian:

Punjabi:

English:

Italian:

Russian:

  • доломит

French:

  • dolomie

Japanese:

  • 苦灰石

Spanish:

  • Dolomita

German:

  • Dolomit

Korean:

  • 백운석, 백운암

Thai:

  • โดโลไมต์

Gujurati:

  • ડોલોમાઇટ

Mandarin Chinese:

  • 白云石

Urdu:

  • ڈولومائٹ

Further Reading / External Links