Kermesite
| Kermesite | |
|---|---|
 |
|
| General and classification | |
| other names |
Red spit shine |
| chemical formula | Sb 2 S 2 O |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.FD.05 ( 8th edition : II / F.11) 02.13.01.01 |
| Crystallographic Data | |
| Crystal system | triclinic (pseudomonoclinic) |
| Crystal class ; symbol | triclinic pinacoidal; 1 |
| Space group | P 1 (No. 2) |
| Lattice parameters |
a = 8.15 Å ; b = 10.71 Å; c = 5.78 Å, α = 102.8 °; β = 110.6 °; γ = 101.0 ° |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 1 to 1.5 |
| Density (g / cm 3 ) | 4.68 |
| Cleavage | completely after {001} |
| Break ; Tenacity | brittle |
| colour | cherry to violet red |
| Line color | brownish red |
| transparency | translucent to opaque |
| shine | Diamond gloss to metallic gloss |
| Crystal optics | |
| Refractive indices |
n α = 2.720 n β = 2.740 n γ = 2.740 |
| Birefringence | δ = 0.020 |
| Optical character | biaxial positive |
Kermesite , outdated also known as red spit gloss , is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the triclinic crystal system with the composition Sb 2 S 2 O, so it is chemically an oxygen-containing antimony sulfide.
Kermesite is translucent to opaque and usually develops needle-like to fibrous, radial-rayed crystals and mineral aggregates from cherry to purple-red color with brownish-red streak color . The surfaces of the kermesite crystals have a strong diamond to metallic sheen .
Etymology and history
Kermesite was first discovered in the "New Hope God" mine near Bräunsdorf (Oberschöna municipality) in Saxony and described in 1737 by Johann Ernst Hebenstreit , who called the mineral Stibium rubrum or red spit-glass ore .
The French mineralogist and chemist Balthazar Georges Sage (1740-1824) referred to the mineral in his 1779 notes as Mine d'Antimoine en plumes (= Kermes mineral natif, German: natural kermes mineral). The old alchemical term Kermes is derived from the Persian word “qurmizq” or from the Arabic “al-qirmiz” and was the name for a red color obtained from insects. François Sulpice Beudant referred to the mineral in his work from 1832 as Kermès or Antimoine rouge . Other synonyms that he has handed down are antimony blende and red mirror ore .
Its name, which is still valid today, kermesite, was finally given to the mineral in 1843 by Edward John Chapman (1821–1904).
classification
In the outdated, but still in use systematics of minerals according to Strunz (8th edition) , the kermesite still belonged to the division of "non-metallic sulfides", where together with cetineite , ottensite and sarabauite it formed the unnamed group II / F.11 .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), classifies the kermesite in the newly defined division of “sulfides of arsenic, alkalis; Sulphides with halides, oxides, hydroxides, H 2 O “. This section is further subdivided according to the type of cations or halogens, oxides or hydroxides occurring in the compound, so that the mineral can be found in the subdivision "with O, OH, H 2 O", where it is classified as the only member is the unnamed group 2.FD.05 .
The systematic of minerals according to Dana , which is mainly used in the English-speaking world , also assigns the kermesite to the class of sulfides and there into the division of "sulfide minerals". Here he is the only member of the unnamed group 02.13.01 within the sub-section “ Sulphides - including selenides and tellurides - oxysulphides ”.
Crystal structure
Kermesite crystallizes triclinically in the space group P 1 (space group no. 2) with the lattice parameters a = 8.15 Å ; b = 10.71 Å; c = 5.78 Å; α = 102.8 °; β = 110.6 ° and γ = 101.0 ° as well as 4 formula units per unit cell .
Education and Locations
Kermesit is a typical secondary mineral formed by weathering of stibnite in antimony - deposits formed. Accompanying minerals are therefore primarily stibnite and solid antimony, but also cervantite , senarmontite , stibiconite and valentinite .
As a rather rare mineral formation, kermesite can sometimes be abundant at different sites, but overall it is not very common. So far (as of 2012) around 200 sites are known. In addition to its type locality “New Hope God” pit near Bräunsdorf in Saxony, the mineral was also found in Germany in the “Segen Gottes” pit near Wiesloch in Baden-Württemberg, in the Brandholz / Goldkronach district in the Bavarian Fichtel Mountains, in the “Help God” pit ( Ore mine Grund ) as well as in the pits "Claus-Friedrich" and " Samson " near Sankt Andreasberg in the Lower Saxon Harz, the Caspari colliery near Uentrop in North Rhine-Westphalia and the pits "Hope" near Martinsknipp and "Apollo" near Raubach in Rhineland- Palatinate come to light.
Pezinok and Pernek in Slovakia, where radial-ray aggregates with crystal needles up to ten centimeters long were found, are known for their extraordinary kermesite finds. After all, crystals up to five centimeters in size emerged in the “Globe and Phoenix Mine” near Kwekwe in Zimbabwe.
In Austria, kermesite has so far only been found in the antimony mine near Stadtschlaining in Burgenland, in Hüttenberger Erzberg in northeast Carinthia and at Wetterbauergraben near Mixnitz / Pernegg an der Mur in Styria.
The only previously known site in Switzerland is in the municipality of Aranno in the canton of Ticino.
Other locations include Australia, Bolivia, China, Finland, France, Greece, Iran, Italy, Japan, Canada, Kyrgyzstan, Columbia, Luxembourg, Mexico, Portugal, Spain, South Africa, the Czech Republic, Turkey, Ukraine, in the United Kingdom ( Great Britain) and in the United States of America (USA).
See also
literature
- Paul Ramdohr , Hugo Strunz : Klockmann's textbook of mineralogy . 16th edition. Ferdinand Enke Verlag, 1978, ISBN 3-432-82986-8 , pp. 451 .
Web links
- Mineral Atlas: Kermesite (Wiki)
- Thomas Witzke : The discovery of Kermesit at www.strahl.org
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. 115 .
- ↑ Webmineral - Kermesite (English)
- ↑ Kermesite . 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; 495 kB ; accessed on May 21, 2017]).
- ↑ a b c d e Mindat - Kermesite (English)
- ^ Iohan Ernesti Hebenstreit: De Antimonio rubro . In: Acta physico-medica Academiæ Cæsareæ Leopoldino-Carolinæ Naturæ Curiosum exhibentia Ephemerides sive Observationes Historias et Experimenta a Celeberrimis Germaniæ et Exterarum Regionum Viris Habita et Communicata Singulari Studio Collecta . tape 4 , 1737, pp. 557-561 ( strahlen.org [PDF; 898 kB ]).
- ↑ a b Thomas Witzke : The discovery of Kermesit at www.strahl.org
- ^ FS Beudant: Kermès, antimoine rouge . In: Traité Élémentaire de Minéralogie . 2nd Edition. Paris 1832, p. 617–618 ( rruff.info [PDF; 80 kB ; accessed on May 21, 2017]).
- ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia . Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 40 ( Dörfler Natur ).
- ↑ Find location list for kermesite at the Mineralienatlas and at Mindat