Beyerite
| Beyerite | |
|---|---|
 |
|
| General and classification | |
| chemical formula |
|
|
Mineral class (and possibly department) |
Carbonates and nitrates |
|
System no. to Strunz and to Dana |
5.BE.35 ( 8th edition : V / C.09) 16a.02.03.01 |
| Similar minerals | Bismuthite , kettnerite |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m |
| Space group | Immm (No. 71) |
| Lattice parameters | a = 3.7729 (5) Å ; b = 3.7742 (7) Å; c = 21.726 (4) Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 2 to 3 |
| Density (g / cm 3 ) | measured: 6.56; calculated: [6.61] |
| Cleavage | no |
| Break ; Tenacity | shell-like |
| colour | gray to gray-green, dark to light yellow, white |
| Line color | White |
| transparency | transparent to opaque |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n ω = 2.130 n ε = 1.970 |
| Birefringence | δ = 0.160 |
| Optical character | uniaxial negative, rarely anomalous biaxial |
| Other properties | |
| Chemical behavior | easily soluble in acids |
Beyerit is a rarely occurring minerals from the mineral class of "carbonates and nitrates" with the chemical composition CaBi 2 [O | CO 3 ] 2 and thus is chemically seen a calcium - bismuth - carbonate with additional oxygen ions .
Beyerite crystallizes in the orthorhombic crystal system and develops thin crystal tablets , which are often arranged in rosette-shaped mineral aggregates . With severe weathering, Beyerite can also have disintegrated into earthy masses. The color of the crystals varies depending on the type of foreign admixture between gray and gray-green, dark to light yellow or white. His line color , however, is always white. Visually, the mineral can hardly be distinguished from the chemically similar bismuthite and kettnerite .
Etymology and history
Beyerit was first described in 1943 by Clifford Frondel in a systematic study of the mineralogy of bismuth oxides and carbonates. The type material comes from Schneeberg in Saxony; Beyerit was in material from the following Pala - Indian Reservation , San Diego County discovered California. It is possible that it was already recognized as independent by Andreas Arzruni in the Schneeberg material. In his preliminary results published posthumously in 1899, however, it is only insufficiently described as basic bismuth carbonate . In 1947 further finds in pegmatites in Colorado followed . The exact crystal structure could only be clarified in 2002.
Frondel named the mineral in honor of the Schneeberg miner and mineralogist Adolph Beyer . He was the first to describe a bismuth carbonate, the so-called bismuthite by August Breithaupt in 1841 as “carbon-acidified bismuth killer or air-acidic bismuth heart” - the material also came from Schneeberg.
Type material of the mineral is at Harvard University in Cambridge under the catalog no. 91593 and 111598 and in the National Museum of Natural History in Washington, DC under catalog no. 94017, C2251 and R2756.
classification
In the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the beyerite belonged to the common mineral class of "carbonates, nitrates and borates" and there to the department of "anhydrous carbonates with foreign anions ", where together with bismuthite , kettnerite and Phosgenite the “phosgenite bismuth group” with the system no. V / C.09 formed.
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 Beyerite to the section of “Carbonates with additional anions; without H 2 O “. This, however, is further subdivided according to the dominant in the connection metals ( cations ), such that the mineral according to its composition in the subsection "With Pb, Bi" is to be found where it is the only member of the unnamed group 5.BE.35 forms .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Beyerite, like the outdated Strunz system, to the common class of “carbonates, nitrates and borates” and there to the category of “carbonates - hydroxyl or halogen”. Here he is the only member of the unnamed group 16a.02.03 within the subsection “Carbonates - Hydroxyl or Halogen with (AB) 3+ (XO 3 ) 2 Z q ”.
Crystal structure
After initial investigations on synthetic material, it was incorrectly assumed in 1948 that beyerite crystallizes tetragonally . However, this assumption did not explain the position of the carbonate group. A new structural analysis in 2002 finally showed that in the orthorhombic crystal system in the space group Immm (space group no. 71) with the lattice parameters a = 3.7729 (5) Š, b = 3.7742 (7) Šand c = 21.726 (4) Šand two formula units per unit cell and a unit cell volume of 309.4 ų crystallizes.
Education and Locations
Beyerite is formed as a secondary mineral through weathering from other bismuth minerals or native bismuth. He therefore found in paragenesis with Bismutit , Atelestit , Preisingerit , pucherite , Eulytin , Namibit , Bismuthinit , Klinobisvanit , Bismutotantalit and dignified bismuth.
As a rare mineral formation, Beyerite could only be detected at a few sites, with around 90 sites (as of 2016) being known to date. In addition to its type locality in the mining district of Schneeberg, the mineral appeared in other places in the Saxon Ore Mountains , including on the dumps and in the shafts of various pits near Neustädtel , Johanngeorgenstadt , Steinbach , Lauta and the Graul near Schwarzenberg . Other sites in Germany are mainly in the Black Forest , such as the Königswart mine near Schönegründ and the Clara mine near Oberwolfach, Neubulach and the Hechtsberg quarry near Hausach in Baden-Württemberg; the Pauline mine near Waldaschaff and the Steinerleinbach quarry near Röhrnbach in Bavaria; the Wolkenhügel pit near Bad Lauterberg in the Harz Mountains in Lower Saxony and the Arme Hilfe pit near Ullersreuth in Thuringia.
In Austria it could be proven at the Hüttenberger Erzberg , in the Czech Republic at Jáchymov (Joachimsthal) and in Spain in the Mina El Valle-Boinás, Belmonte de Miranda , Asturias . There are numerous sites in the USA, for example in the Stewart Mine, Pala district, in California and in the Mesa Grande district, San Diego County. There are other US deposits in New Mexico , Arizona , Colorado , Nevada and Utah . In Namibia , the mineral can be found together with Namibite on the Mesopotamia 504 farm near Khorixas . It forms small veins in the A Lone Hand Mine, Malbon, Queensland , Australia.
See also
literature
- Clifford Frondel : Mineralogy of the oxides and carbonates of bismuth . In: American Mineralogist . tape 28 , 1943, pp. 521-535 ( minsocam.org [PDF; 978 kB ; accessed on August 20, 2017]).
- Eberhardt William Heinrich : Beyerite from Colorado . In: American Mineralogist . tape 32 , 1947, pp. 660–669 ( minsocam.org [PDF; 633 kB ; accessed on August 20, 2017]).
- Helmut Schrätze , Karl-Ludwig Weiner : Mineralogy. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 351 .
- Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 715 .
- Joel D. Grice: A solution to the crystal structure of bismutite and beyerite . In: The Canadian Mineralogist . tape 40 , 2002, p. 693–698 ( rruff.info [PDF; 649 kB ; accessed on August 20, 2017]).
Web links
Individual evidence
- ↑ a b c d Joel D. Grice: A solution to the crystal structure of bismutite and beyerite . In: The Canadian Mineralogist . tape 40 , 2002, p. 693–698 ( rruff.info [PDF; 649 kB ; accessed on August 20, 2017]).
- ^ A b 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. 300 .
- ↑ Webmineral - Beyerite (English)
- ↑ a b Beyerite . 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; 64 kB ; accessed on August 20, 2017]).
- ↑ a b c d Mindat - Beyerite
- ^ Mineralienatlas: Beyerit
- ↑ Andreas Arzruni, Konstantin Thaddéeff: New minerals from Chile, a new occurrence of Utahite and a new bismuth carbonate from Schneeberg . In: Zeitschrift für Krystallographie . tape 31 , 1899, pp. 246–247 ( rruff.info [PDF; 1.7 MB ; accessed on August 20, 2017]).
- ↑ Thomas Witzke : Discovery of Beyerite at www.strahl.org (accessed on August 20, 2017)
- ↑ Mindat - Number of localities for Beyerite
- ↑ Find location list for Beyerite in the Mineralienatlas and Mindat