Kutnohorit
| Kutnohorit | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | CaMn [CO 3 ] 2 |
|
Mineral class (and possibly department) |
Carbonates (and relatives) |
|
System no. to Strunz and to Dana |
5.AB.10 ( 8th edition : V / B.03) 02/14/01/03 |
| Crystallographic Data | |
| Crystal system | trigonal |
| Crystal class ; symbol | trigonal-rhombohedral; 3 |
| Space group | R 3 (No. 148) |
| Lattice parameters | a = 4.85 Å ; c = 16.22 Å |
| Formula units | Z = 3 |
| Frequent crystal faces | R 3 |
| Twinning | 148 |
| Physical Properties | |
| Mohs hardness | 3.5 to 4 |
| Density (g / cm 3 ) | measured: 3.12; calculated: 3.15 |
| Cleavage | completely according to {10 1 1} |
| Break ; Tenacity | slightly scalloped, brittle |
| colour | white, gray, pink, yellowish |
| Line color | White |
| transparency | translucent |
| shine | Glass gloss, matt |
| Crystal optics | |
| Refractive indices |
n ω = 1.710 to 1.727 n ε = 1.519 to 1.535 |
| Birefringence | δ = 0.191 to 0.192 |
| Optical character | uniaxial negative |
Kutnohorite , also known as kutnahorite or mangandolomite , is a mineral from the mineral class of " carbonates ( and relatives )", which can be abundant in various locations, but is generally not very common. It crystallizes in the trigonal crystal system with the composition CaMn [CO 3 ] 2 , so it is chemically a calcium - manganese carbonate.
Kutnohorit mainly develops polycrystalline, radial, granular or massive mineral aggregates of white, gray, pink, yellowish color with white streak color .
Together with dolomite and ankerite , kutnohorite forms a complete series of mixed crystals .
Etymology and history
Kutnahorite was first found in the "Poličany" near Kutná Hora in the Czech region of Central Bohemia and described in 1901 by Antonín Bukovský (1865–1950), who named the mineral after this type of locality .
classification
In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the kutnohorite belonged to the common mineral class of "carbonates, nitrates and borates " and there to the department of "anhydrous carbonates without foreign anions ", where together with ankerite , benstonite , Dolomite , ewaldite , huntite , minrecordite and norsethite formed a separate group.
The 9th edition of Strunz's mineral systematics, valid since 2001 and used by the International Mineralogical Association (IMA), assigns the kutnohorite to the class of "carbonates and nitrages" (the borates now form a separate class) and there into the department of " Carbonates without additional anions; without H 2 O “. However, this section is further subdivided according to the group affiliation of the cations involved , so that the mineral can be found according to its composition in the sub-section "alkaline earth (and other M 2+ ) carbonates", where it is only found together with anchorite, dolomite and minrecordite the "Dolomite Group" with the system no. 5.AB.10 forms.
The systematics of minerals according to Dana assigns the kutnohorite like the outdated Strunz'sche systematics to the common class of "carbonates, nitrates and borates" and there in the department of "anhydrous carbonates". Here it is together with dolomite, anchorite and minrecordite in the "dolomite group (Trigonal: R 3 )" with the system no. 02/14/01 to be found in the subsection of " Anhydrous carbonates with the formula A + B 2+ (CO 3 ) 2 ".
Crystal structure
Kutnohorite crystallizes trigonally in the space group R 3 (space group number 148) with the lattice parameters a = 4.85 Å and c = 16.22 Å as well as 3 formula units per unit cell .
properties
Under UV light , some Kutnohorites show an orange to pink fluorescence , similar to that of neon-colored highlighters .
Education and Locations
Kutnohorite forms hydrothermally or metamorphically in various deposits, mostly in paragenesis with rhodochrosite , aragonite and calcite , but also with anchorite , quartz or other minerals.
So far (as of 2011) Kutnohorite has been found at around 150 sites worldwide. In addition to its type locality Kutná Hora, the mineral is also available in the Czech Republic at Lomnice u Sokolova and Chvaletice .
In Germany, the mineral was previously found on the Hartkoppe in the Spessart in Bavaria; in the Grund ore mine (“Help of God” mine) and in the Bülten-Adenstedt mine (Emilieschacht) in Lower Saxony; near Elbingerode in Saxony-Anhalt and in the Freiberg district in Saxony.
In Austria, Kutnohorit performed at Hüttenberg and Bad St. Leonhard in Lavanttal in Carinthia, in the Salzburg Tennengebirge , at glassworks in the municipality of Gressenberg and in Veitschtal in Styria.
In Switzerland, the mineral has so far been found in the Albula Valley , the Hinterrheintal and in the municipality of Bregaglia in the canton of Graubünden and in the Turtmann valley in the canton of Valais.
Other locations are Argentina , Australia , Belgium , Brazil , Bulgaria , Chile , China , France , Gabon , Ghana , India , Indonesia , Italy , Japan , Canada , Kazakhstan , Mexico , Namibia , New Zealand , Norway , Peru , Poland , Romania , Russia , Sweden , Slovakia , South Africa , Turkey , Ukraine , Hungary and the United States of America (USA).
See also
literature
- Kutnohorite , in: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 62.2 kB )
- Paul Ramdohr , Hugo Strunz : Klockmann's textbook of mineralogy . 16th edition. Ferdinand Enke Verlag, 1978, ISBN 3-432-82986-8 , pp. 573 .
- Petr Korbel, Milan Novák: Encyclopedia of Minerals . Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 118 (Kutnahorite) .
Web links
- Mineral Atlas: Kutnohorit (Wiki)
Individual evidence
- ↑ Webmineral - Kutnohorite (English)
- ^ A b c Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 287 .
- ↑ a b c Mindat - Kutnohorite (English)
- ↑ Mindat - Bukovskýite (named after Antonín Bukovský)
- ↑ Find location list for Kutnohorit at the Mineralienatlas and at Mindat