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Kutnohorite  (Kutnahorite)
Current inventory:  0 gems
 

  
Kutnohorite is named for its first described occurrence at Kutná Hora, Bohemia, Czech Republic (the original label translated as Kutnohorite).

Discovered in 1901;   IMA status: Valid (IMA approved). (pre-IMA; Grandfathered).

Chemistry

Chemical Formula:

Ca(Mn,Mg,Fe)(CO₃)₂

Calcium Magnesium Carbonate

Molecular Weight:

205.94 gm

Composition: 

Classification

Mineral Classification:

Carbonates

Strunz 8th Ed. ID:

5/B.03-30

Nickel-Strunz 10th Ed. ID:

5.AB.10

5 : CARBONATES (NITRATES)
A : Carbonates without additional anions, without H₂O
B : Alkali-earth (and other M²⁺) carbonates

Related to:

Dolomite Group. Ankerite-Kutnohorite Series.

Varieties:

Parakutnohorite

Synonyms:

Kutnahorite, Kutnohorrite

Crystal Data

Crystallography:

Trigonal - Rhombohedral

Crystal Habit:

In polycrystalline spherules, to 2 cm, aggregates, and cleavages.

Twinning:

None

Physical Properties

Cleavage:

[1011] Perfect, [1011] Perfect, [1011] Perfect

Fracture:

Sub-Conchoidal

Tenacity:

Brittle

Moh's Hardness:

3.5 - 4.0

Density:

3.12 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

White, pale Rose to bright Pink, light to medium Brown

Transparency:

Translucent

Luster:

Vitreous to Pearly, Dull

Refractive Index:

1.535 - 1.727  Uniaxial ( - )

Birefringence:

0.1910 - 0.1920

Pleochroism:

None

Occurances

Geological Setting:

Typically in deposits associated with manganiferous sediments.

Common Associations:

Aragonite, Calcite, Rhodochrosite

Type Locality:

Policany, Kutná Hora (Kuttenberg), Central Bohemia Region, Czech Republic

Year Discovered:

1901

View mineral photos:

Kutnohorite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Kutnohorite, also spelled as Kutnahorite, is a rare carbonate mineral. It is a member of the Dolomite Group and is difficult to distinguish from Dolomite except that Kutnohorite has greater density.

Analyzed material, shown to have the dolomite structure type, occurs at: Kutná Hora and Chvaletice, Czech Republic. At Långban, Värmland, Sweden. From near Levane, Tuscany, Italy. In the USA, at Franklin and Sterling Hill, Ogdensburg, Sussex Co., New Jersey; in the Sunnyside and Silver King mines, Silverton district, San Juan Co., Colorado; in the Longvale quarry, Laytonville, Mendocino Co., California; from Bald Knob, Alleghany Co., North Carolina. At Mont Saint-Hilaire, Quebec, Canada. In the Providencia district, Zacetecas, Mexico. Fine examples from the N’Chwaning mine, near Kuruman, South Africa. In Japan, in the Hoei tin mine, Oita Prefecture, from the Chichibu mine, Saitama Prefecture, and at the Ryujima mine, 15 km southwest of Matsumo, Nagano Prefecture. From Broken Hill, New South Wales, Australia.
 

  
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