Ramdohrite
| Ramdohrite | |
|---|---|
 |
|
| General and classification | |
| chemical formula | Pb 12 Ag 6 Sb 22 S 48 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.JB.40a ( 8th edition : II / E.23) 04/03/15/06 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 1 / n (No. 14, position 2) |
| Lattice parameters |
a = 13.08 Å ; b = 19.24 Å; c = 8.73 Å β = 90.3 ° |
| Formula units | Z = 1 |
| Twinning | lamellar and crossover twins |
| Physical Properties | |
| Mohs hardness | 2 |
| Density (g / cm 3 ) | measured: 5.43; calculated: 5.64 |
| Cleavage | Please complete |
| Break ; Tenacity | uneven, brittle |
| colour | gray-black with a bluish tinge; white in polished sections |
| Line color | grey black |
| transparency | opaque |
| shine | Metallic luster |
Ramdohrite is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the monoclinic crystal system with the chemical composition Pb 12 Ag 6 Sb 22 S 48 and develops mostly long prismatic, lanceolate crystals as well as lamellar and cross twins of bluish-gray to gray-black color with gray-black line color . A metallic sheen appears on the surfaces of the opaque crystals and a white sheen on freshly polished surfaces.
Etymology and history
Ramdohrite was first discovered in the " Chocaya Mine" in the Bolivian Department of Potosí and described in 1930 by Friedrich Ahlfeld , who named the mineral in honor of Paul Ramdohr (1890–1985) and his services to the study of opaque minerals, especially ores.
classification
Already in the outdated, but still in use 8th edition of the mineral classification according to Strunz , ramdohrite belonged to the mineral class of "sulfides and sulfosalts" and there to the general division of "sulfosalts (S: As, Sb, Bi = x)", where it belongs together with andorite , fizélyite , roshchinite and uchucchacuait formed the unnamed group II / E.23 .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns ramdohrite to the class of “sulfides and sulfosalts”, but in the more finely structured section of “sulfosalts with PbS as a model " a. This is further subdivided according to the crystal structure or the dominant cation in the compound, so that the mineral can be found according to its composition in the subdivision of " Galena derivatives with lead (Pb)", where it can be found together with andorite IV , andorite VI , Fizélyit , Gustavit , Lillianit , Roshchinit, Treasurit , Uchucchacuait, Vikingit and Xilingolit the "Lillianitgruppe" with the system no. 2.JB.40a forms.
The systematics of minerals according to Dana also assigns ramdohrite to the class of "sulfides and sulfosalts" and there in the department of "sulfosalts". Here he is also a member of the " Lillianite group (Orthorhombic, with the composition A m B n S 6 with A = Pb, Ag, Mn and B = Sb, Bi) " with the system no. 04/03/15 within the sub-section of "sulfosalts with the ratio 3> z / y and the composition (A + ) i (A 2+ ) j [B y C z ], A = metals, B = semi-metals, C = non-metals" .
Crystal structure
Ramdohrite crystallizes monoclinically in the space group P 2 1 / n (space group no. 14, position 2) with the lattice parameters a = 13.08 Å ; b = 19.24 Å; c = 8.73 Å and β = 90.3 ° and one formula unit per unit cell .
Education and Locations
Ramdohrite forms in hydrothermally formed veins in fine-grained quartz . Besides quartz, accompanying minerals include andorite , jamesonite , pyrite , sphalerite and stannite .
As a rare mineral formation, ramdohrite could only be detected in a few places, whereby so far (as of 2017) around 30 sites are known. In addition to its type locality "Chocaya Mine", the mineral was also found in Bolivia in the neighboring " Animas Mine", the " Siete Suyos Mine" and at Portugalete and Tatasi in the Sur Chichas province . In addition, ramdohrite could be found in the " Tornohuaico Mine" ( Municipio Porco , also Potosí) and the "San José Mine" near Oruro in the Antonio Quijarro province .
Other locations are the "Pirquitas" deposit near Abra Pampa in the Argentine department of Rinconada ; the Sedeftche (Sedefche) deposit in the Bulgarian Kardzhali Oblast ; some find spots in different Chinese regions; the “Metsämonttu Mine” in the Finnish municipality of Kisko ; Charbes ( canton Villé ), the "Marsanges Mine" ( canton Langeac ) and Bazoges-en-Paillers ( canton Les Herbiers ) in France; Agios Konstantinos in the Greek municipality of Lavrio ; the "Guitarra Mine" at Temascaltepec in Mexico ; Mofjellet in the Norwegian municipality of Rana (Nordland) ; the "Herja Mine" in the Romanian municipality of Băița (Hunedoara) (Hungarian: Kisbánya ); Ust-Nera and Verkhoyansk in the East Siberian Republic of Sakha (Yakutia) in Russia; Herichová near Chyžné and Kremnica ( Okres Banská Bystrica ) and Zlatá Baňa ( Okres Prešov ) in Slovakia as well as West Bishop in Inyo County in California, Back Forty in Menominee County (Michigan) and North Bend in King County (Washington) in the United States from America.
See also
literature
- Friedrich Ahlfeld: Ramdohrite, a new mineral from Bolivia . In: Centralblatt für Mineralogie, Geologie und Paläontologie . tape 8 , 1930, p. 365–367 ( rruff.info [PDF; 210 kB ; accessed on January 22, 2017]).
- WF Foshag: New mineral names . In: American Mineralogist . tape 16 , 1931, pp. 132-132 ( rruff.info [PDF; 48 kB ; accessed on January 22, 2017]).
- Emil Makovicky, William G. Mumme, Robert William Gable: The crystal structure of ramdohrite, Pb 5.9 Fe 0.1 Mn 0.1 In 0.1 Cd 0.2 Ag 2.8 Sb 10.8 S 24 : A new refinement . In: American Mineralogist . tape 98 , 2013, p. 773-779 , doi : 10.2138 / am.2013.4146 .
Web links
- Mineral Atlas: Ramdohrite (Wiki)
- RRUFF Database-of-Raman-spectroscopy - Ramdohrite
- American-Mineralogist-Crystal-Structure-Database - Ramdohrite
Individual evidence
- ↑ a b c d e 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. 142 .
- ↑ Webmineral - Ramdohrite (English)
- ↑ Ramdohrite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 54 kB ]).
- ↑ Mindat - Number of localities for Ramdohrite
- ↑ Find location list for ramdohrite in the Mineralienatlas and in Mindat