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Origin Story

Dolomite was first described in 1791 by the French mineralogist Déodat Gratet de Dolomieu, whose name graces both the mineral and the Dolomite Alps in Italy. Its identification as a unique mineral species predates the establishment of formal mineralogical authorities, yet today it is fully approved and cataloged by the International Mineralogical Association. Dolomite’s origin story is deeply intertwined with the study of carbonate rocks, especially the distinction between limestone and dolostone, and its discovery helped clarify the processes of sedimentary rock formation.

Classification

Dolomite belongs to the carbonate mineral group, specifically classified as a double carbonate of calcium and magnesium. In the Dana system, it is coded as 16a.1.2.1, and in the Strunz classification as 5.AB.10. Its placement within these schemes reflects both its chemical makeup and its trigonal crystal system. Dolomite is a key species within the broader family of carbonate minerals, which also includes calcite and aragonite.

Appearance or Form

Dolomite typically forms well-developed rhombohedral crystals, often appearing as saddle-shaped or blocky structures. Its color ranges from white and pink to gray and brownish hues. The mineral exhibits a vitreous to pearly luster and is characterized by perfect cleavage in three directions, which gives rise to its distinctive geometric forms. Dolomite’s surface may feel smooth, and its crystals are often transparent to translucent, with a brittle fracture.

Behavior or Usage

Dolomite interacts with dilute hydrochloric acid, producing a slow effervescence—a trait that distinguishes it from more reactive carbonates like calcite. In human use, dolomite serves as a vital industrial mineral: it is a source of magnesium, acts as a flux in steel production, is used in glass manufacturing, and serves as an aggregate in construction. It also finds use as a soil conditioner and, occasionally, as a decorative stone or minor gemstone.

Merchandise & Prints

Bring this kind into your world � illustrated posters, mugs, and shirts.

Dolomite Dolomite Poster

Dolomite Poster

Archival print, museum-grade paper

Dolomite Dolomite Mug

Dolomite Mug

Stoneware mug, dishwasher safe

Dolomite Dolomite Shirt

Dolomite Shirt

Soft cotton tee, unisex sizes

Attributes & Insights

Taxon-Specific Insights

🌍Cultural Significance

The name "Dolomite" is immortalized in the Dolomite Alps, a region celebrated for its dramatic landscapes and geological heritage. The mineral’s discovery marked a turning point in the understanding of carbonate rocks, influencing both scientific thought and regional identity. While dolomite itself is not commonly featured in art or myth, its presence in architecture and its role in shaping iconic mountain ranges lend it a subtle but enduring cultural resonance.

📌Notable Facts

  • Dolomite forms extensive sedimentary beds known as dolostone, which can cover vast geological regions.
  • It is less reactive to acids than calcite, making it more resistant to weathering in natural environments.
  • The mineral’s perfect rhombohedral cleavage makes its crystals easily recognizable among carbonates.
  • Dolomite is occasionally used as a minor gemstone due to its attractive crystal forms and colors.
  • Its discovery led to the naming of the Dolomite Alps, one of Europe’s most famous mountain ranges.

🧪Chemical Composition

Chemical Formula: CaMg(CO₃)₂. Dolomite is a double carbonate mineral, containing both calcium and magnesium ions bonded with carbonate groups.

Visual Variations

High resolution studio photograph of a single specimen of Dolomite
High resolution studio photograph of a single specimen of Dolomite
Macro shot of Dolomite, of the taxonomy minerals, showing detailed crystal structure and surface texture
Macro shot of Dolomite, of the taxonomy minerals, showing detailed crystal structure and surface texture
Naturalistic scene featuring Dolomite in its typical geological environment, as categorized by minerals
Naturalistic scene featuring Dolomite in its typical geological environment, as categorized by minerals
Cross-sectional illustration of Dolomite, of the taxonomy minerals
Cross-sectional illustration of Dolomite, of the taxonomy minerals
Depiction of Dolomite, as it is used or valued in human culture
Depiction of Dolomite, as it is used or valued in human culture

Composition & Context

Taxon-Specific Insights

🔷Crystal Structure

Dolomite crystallizes in the trigonal system, specifically within the rhombohedral class (space group R3̅). Its crystals are typically rhombohedral in shape, with perfect cleavage along three directions, giving rise to its characteristic geometric forms.

Physical Properties

  • Hardness: 3.5–4 on the Mohs scale
  • Color: White, pink, gray, brownish
  • Luster: Vitreous to pearly
  • Cleavage: Perfect in three directions (rhombohedral)
  • Fracture: Brittle
  • Specific Gravity: ~2.85

🌍Geological Occurrence

Dolomite is abundant in sedimentary rocks, forming vast beds known as dolostone, often through the replacement of limestone during diagenesis. It also occurs in hydrothermal veins, metamorphic rocks, and as a secondary mineral in ore deposits. Notable localities include the Dolomite Alps in Italy, Missouri, and the Tri-State district in the USA. Dolomite is commonly associated with limestone, marble, and other carbonate rocks.

Varieties And Synonyms

  • Synonyms: Bitter spar, dolomitic limestone, dolostone
  • Varieties: Regional variants such as Tri-State dolomite; dolostone refers to the rock composed predominantly of dolomite mineral.

Industrial And Technological Uses

  • Source of magnesium for chemical and metallurgical industries
  • Flux in steel production to remove impurities
  • Raw material in glass manufacture
  • Aggregate in construction and road building
  • Soil conditioner to adjust pH and add magnesium
  • Used as a decorative stone and, rarely, as a minor gemstone

🔍Identification Tips

  • Look for rhombohedral crystals with perfect cleavage in three directions.
  • Test with dilute hydrochloric acid: dolomite effervesces slowly, unlike calcite’s rapid reaction.
  • Note color variations—white, pink, gray, or brownish—and a vitreous to pearly luster.
  • Check hardness (3.5–4 Mohs) and brittle fracture for confirmation.

Care And Handling

Store dolomite specimens in a dry environment to prevent weathering. Clean gently with a soft brush and avoid harsh chemicals, as the mineral is slightly soluble in acids. Handle with care to prevent chipping, as dolomite is brittle and can fracture easily. Display away from direct sunlight to preserve color in decorative samples.

Famous Specimens

  • The Dolomite Alps in Italy are named for the mineral and are renowned for their spectacular exposures of dolostone.
  • Classic saddle-shaped dolomite crystals from the Tri-State district (USA) are prized by collectors.
  • Large, well-formed rhombohedral crystals from Missouri are featured in many museum collections.

Faq

  • What is the chemical formula of dolomite?
    Dolomite’s formula is CaMg(CO₃)₂, representing calcium magnesium carbonate.
  • How can you distinguish dolomite from calcite?
    Dolomite reacts slowly with dilute hydrochloric acid, while calcite reacts vigorously; dolomite also has a slightly higher hardness and distinctive rhombohedral cleavage.
  • Where is dolomite commonly found?
    Major deposits are found in the Dolomite Alps (Italy), Missouri (USA), and the Tri-State district (USA), often forming sedimentary beds called dolostone.