Bariopharmacosiderite
| Bariopharmacosiderite | |
|---|---|
 |
|
| General and classification | |
| other names |
formerly barium pharmacosiderite |
| chemical formula | (Ba, Ca) 0.5-1 Fe 3+ 4 [(OH) 4-5 | (AsO 4 ) 3 ] • 5-7H 2 O |
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.DK.10 ( 8th edition : VII / D.47) 08.22.01.03 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | tetragonal-scalenohedral; 4 2 m |
| Room group (no.) | P 4 2 m (No. 111) |
| Lattice parameters | a = 7.947 Å ; c = 8.049 Å |
| Formula units | Z = 8 |
| Physical Properties | |
| Mohs hardness | 2.5 to 3 |
| Density (g / cm 3 ) | measured: 3.05; calculated: 3.07 |
| Cleavage | good after {100} |
| Break ; Tenacity | not defined |
| colour | yellow to brownish yellow, orange to red, green, bluish |
| Line color | white to brownish white |
| transparency | transparent to translucent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n ω = 1.728 n ε = 1.718 |
| Birefringence | δ = 0.010 |
| Optical character | uniaxial alternating |
| Other properties | |
| Chemical behavior | easily soluble in warm hydrochloric acid (1: 1) |
Bariopharmacosiderite (formerly barium pharmacosiderite ) is a rather rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the tetragonal crystal system with the chemical composition (Ba, Ca) 0.5–1 Fe 3+ 4 [(OH) 4–5 | (AsO 4 ) 3 ] · 5–7H 2 O, so it is a water-containing barium - Calcium - iron arsenate. The elements barium and calcium indicated in the round brackets can represent each other in the formula ( substitution , diadochy), but are always in the same proportion to the other components of the mineral.
Bariopharmakosiderite develops only small crystals up to about one millimeter in size with a pseudocubic habit of yellow to brownish-yellow, orange to red or rarely green to bluish color.
Etymology and history
Bariopharmacosiderite was first discovered in the Clara mine near Oberwolfach in the Black Forest in southwest Baden-Württemberg and was described in 1966 by Kurt Walenta , who made the mineral based on its close relationship to pharmacosiderite (KFe 3+ 4 [(OH) 4 | (AsO 4 )) 3 ] · 6-7H 2 O) with a dominant barium content called barium pharmacosiderite .
In the course of the 2008 publication "Tidying up Mineral Names: an IMA-CNMNC Scheme for Suffixes, Hyphens and Diacritical marks" to clean up and standardize mineral names, the name was renamed to bariopharmacosiderite due to the superfluous hyphen.
classification
Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the bariopharmacosiderite belonged to the class of "phosphates, arsenates and vanadates" and there to the department of "water-containing phosphates with foreign anions ", where together with alumopharmacosiderite , pharmacosiderite and Natropharmakosiderit the "pharmacosiderite group" with the system no. VII / D.47 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 bariopharmacosiderite to the category of “phosphates etc. with additional anions; with H 2 O “. However, this is further subdivided according to the relative size of the cations involved and the molar ratio of the other anions (OH etc.) to the phosphate, arsenate or vanadate complex (RO 4 ), so that the mineral is classified in the sub-section “With large and medium-sized cations; (OH etc.): RO 4 > 1: 1 and <2: 1 “can be found where it is found together with pharmacosiderite, hydronium pharmacoalumite ( IMA 2012-050 ), hydronium pharmacosiderite ( IMA 2010-014 ), natropharmakoalumite ( IMA 2010-009 ), and Natropharmakosiderit Pharmakoalumit (formerly Alumopharmakosiderit ) "Pharmakosideritgruppe" with the system number. 8.DK.10 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns bariopharmacosiderite to the class of "phosphates, arsenates and vanadates" and there to the category of "water-containing phosphates, etc., with hydroxyl or halogen". Here it can be found in the unnamed group 42.08.01 within the subdivision “ Water-containing phosphates etc., with hydroxyl or halogen with (AB) 7 (XO 4 ) 4 Z q × x (H 2 O) ”.
Crystal structure
Bariopharmacosiderite crystallizes tetragonally in the space group P 4 2 m (space group no. 111) with the lattice parameters a = 7.947 Å and c = 8.049 Å and 8 formula units per unit cell .
properties
Bariopharmakosiderit is easily soluble in warm, dilute hydrochloric acid (mixing ratio 1: 1).
Education and Locations
Bariopharmacosiderite forms secondary from arsenopyrite and tennantite in the oxidation zone of iron and arsenic deposits . As accompanying minerals may include Arseniosiderit , barite , fluorite , goethite , Skorodit , limonite , quartz , Segnitit , Yukonit and Zeunerit occur.
As a rather rare mineral formation, bariopharmacosiderite can be partly abundant at different sites, but overall it is not very common. A total of around 130 sites are known to date (as of 2013). In addition to its type of locality , the "Clara mine" near Oberwolfach, the mineral appeared in Germany in many places in the Black Forest in Baden-Württemberg such as Freudenstadt , Menzenschwand , Neubulach , Todtnau and Wittichen . Bariopharmacosiderite is also known from some places in the Spessart in Bavaria, from Hohenstein (Reichenbach) in Hesse, from several places in the Harz Mountains in Lower Saxony, from Nunkirchen in the Saarland, from Ehrenfriedersdorf , Schneeberg and other places in the Ore Mountains in Saxony and from Neumühle and Stempeda in Thuringia.
In Austria, bariopharmacosiderite was found on the Sperkerriegel near Wiesmath in Lower Austria; on the Ödenkar in the Kreuzkogel massif near Bad Gastein and on a prehistoric dump near Schwarzleo ( Leogang municipality ) in Salzburg; on the Weißen Schrofen in the Schwaz district , on the Graschberg near Thierbach (community Wildschönau) and near Flirsch in North Tyrol and on the Vilifau Alp in the Rellstal near the community of Vandans in Vorarlberg.
In Switzerland, the mineral has so far only been discovered on the Mürtschenalp (Murgtal) in the canton of Glarus and the “La Barma” mine near Saint-Luc VS in the canton of Valais .
Other locations are in Australia, Chile, China, France, Greece, Italy, Japan, Morocco, Portugal, Slovakia, Spain, South Africa, Taiwan, the Czech Republic, Hungary, England in the United Kingdom (UK) and in Colorado, California , Nevada, New Jersey and Utah in the United States of America (USA).
See also
literature
- Kurt Walenta: Contributions to the knowledge of rare arsenate minerals with special consideration of occurrences in the Black Forest. In: Tschermaks Mineralogische und Petrographische Mitteilungen. Vol. 11 (1966), pp. 121-164.
- M. Fleischer: New mineral names. In: American Mineralogist. Volume 52 (1967), pp. 1579–1589 ( PDF 781.3 kB )
- Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 514 ( barium pharmacosiderites ) .
- SL Hager, P. Leverett, PA Williams, SJ Mills, DE Hibbs, M. Raudsepp, AR Kampf, WD Birch: The single-crystal X-ray structures of bariopharmacosiderite-C, bariopharmacosiderite-Q and natropharmacosiderite. In: The Canadian Mineralogist. Volume 48 (2010), pp. 1477-1485.
Web links
- Mineral Atlas: Bariopharmacosiderite (Wiki)
- Database-of-Raman-spectroscopy - Bariopharmacosiderite
- American-Mineralogist-Crystal-Structure-Database - Bariopharmacosiderite
Individual evidence
- ↑ a b c d Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 5th completely revised and supplemented edition. Weise, Munich 2008, ISBN 978-3-921656-70-9 .
- ↑ a b c d Webmineral - Bariopharmacosiderite
- ↑ a b c American-Mineralogist-Crystal-Structure-Database - Bariopharmacosiderite
- ↑ a b c d Mindat - Bariopharmacosiderite
- ^ A b Ernst AJ Burke: Tidying up Mineral Names: an IMA-CNMNC Scheme for Suffixes, Hyphens and Diacritical marks. In: Mineralogical Record , Volume 39, No. 2 (March-April 2008); PDF 2.7 MB
- ↑ Mindat - Number of localities for bariopharmacosiderite
- ↑ Find location list for bariopharmacosiderite at the Mineralienatlas and at Mindat