Arsenopyrite
| Arsenopyrite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | FeAsS |
|
Mineral class (and possibly department) |
Sulphides / sulphosalts, metal: sulfur (selenium, tellurium) <1: 1 |
|
System no. to Strunz and to Dana |
2.EB.20 ( 8th edition : II / C.09) 02.12.04.01 |
| Similar minerals | Löllingite, skutterudite, chloanthite |
| Crystallographic Data | |
| Crystal system | monoclinic, pseudo-orthorhombic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 1 / c (No. 14) |
| Lattice parameters |
a = 5.74 Å ; b = 5.65 Å; c = 5.76 Å β = 110.6 ° |
| Formula units | Z = 4 |
| Twinning | generally according to {100} and {001}, triplets and polysynthetic twins are also possible |
| Physical Properties | |
| Mohs hardness | 5.5 to 6 |
| Density (g / cm 3 ) | measured: 6.07; calculated: 6.18 |
| Cleavage | clear after {101}, indistinct after {010} |
| Break ; Tenacity | uneven |
| colour | silver white, steel gray; dark or colored |
| Line color | gray-black to black |
| transparency | opaque |
| shine | Metallic shine, dark or tinged with color |
| magnetism | magnetic after heating |
| Other properties | |
| Special features | bitter odor after breaking open |
Arsenopyrite date, or by mining including as arsenopyrite , poison gravel or Mißpickel known, a frequently occurring is mineral from the mineral class of "sulfides and sulfosalts" with the idealized chemical composition FeAsS and chemical terms, a iron - arsenic - sulphide .
Arsenopyrite crystallizes in the monoclinic crystal system and develops tabular to prismatic or blocky crystals , which are mostly striped along the c-axis. Pseudo-octahedral or pseudo-orthorhombic crystal twins and star-shaped triplets are also common. It is also found in the form of granular to compact mineral aggregates .
The mineral is opaque in every form and shows a metallic sheen on the surfaces of the freshly tin-white to steel-gray crystals . Over time, however, these become dark or brightly colored. His line color , on the other hand, is always gray-black to black.
Etymology and history
Chemically arsenopyrite is an isomorphous mixture of Löllingit ( Eisendiarsenid , FeAs 2 ) and pyrite ( iron disulfide , FeS 2 ). It is from this composition that it owes its name.
Arsenopyrite was first described in 1847 by Ernst Friedrich Glocker .
classification
Already in the outdated 8th edition of the mineral classification according to Strunz , arsenopyrite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with M: S <1: 1", where it was named after the "arsenopyrite group" the system no. II / C.09 and the other members Glaukodot and Gudmundit .
In the last revised and updated Lapis mineral directory by Stefan Weiß in 2018 , which, out of consideration for private collectors and institutional collections, is still based on this classic system of Karl Hugo Strunz , the mineral was given the system and mineral number. II / D.22-10 . In the “Lapis system” this also corresponds to the section “Sulphides with metal: S, Se, Te <1: 1”, where arsenopyrite forms the “arsenopyrite group” together with Alloklas , Glaukodot, Gudmundite, Osarsite and Ruarsite .
In contrast, the 9th edition of Strunz's mineral systematics, which has been in effect since 2001 and was updated by the International Mineralogical Association (IMA) until 2009, classifies arsenopyrite in the category of “metal sulfides with M: S ≤ 1: 2”. This is further subdivided according to the exact molar ratio and the predominant metals in the compound, so that the mineral can be found in the sub-section "M: S = 1: 2, with Fe, Co, Ni, PGE etc." according to its composition , where together with Gudmundit, Osarsit, Paxit and Ruarsit the “arsenopyrite group” with the system no. 2.EB.20 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking area , also assigns arsenopyrite to the class of "sulfides and sulfosalts" and there into the category of "sulfide minerals". Here, too, he is in the " arsenopyrite group (monoclinic: P 2 1 / c (pseudo-orthorhombic)) " with the system no. 02.12.04 within the subsection "Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 2".
Chemism
The idealized, theoretical composition of arsenopyrite (FeAsS) consists of 34.30% iron (Fe), 46.01% arsenic (As) and 19.69% sulfur (S). However, the chemical composition generally varies from FeAs 1.1 S 0.9 to FeAs 0.9 S 1.1 . In addition, small amounts of cobalt (Co) and bismuth (Bi) were found in natural mineral samples .
Crystal structure
Arsenopyrite crystallizes monoclinically in the space group P 2 1 / c (space group no. 14) with the lattice parameters a = 5.74 Å ; b = 5.65 Å; c = 5.76 Å and β = 110.6 ° as well as 4 formula units per unit cell .
properties
Arsenopyrite can be recognized by its bitter odor when broken or in powder form. It dissolves in sulfuric acid with the separation of sulfur . A sample placed on carbon forms a black, magnetic ball in front of the blowtorch.
Modifications and varieties
Danaite ( cobalt arsenopyrite , cobalt arsenic gravel ) is the only known variety so far . Due to a mass content of about 6 to 12% cobalt , Danait is somewhat softer than arsenopyrite.
Education and Locations
Arsenopyrite forms hydrothermally in mineral veins and greisen , as well as through metamorphosis in skarn , gneiss and mica schist . It is often found in paragenesis with chalcopyrite , galena , cassiterite , pharmacosiderite , pyrrhotite , pyrite , scheelite and many others. Even gold and silver are often mixed mechanically in the finest form.
Arsenopyrite is a frequent mineral formation that can be found in many places, with around 5600 sites (as of 2010) being known to date. In Germany the mineral was found in Freiberg , Ehrenfriedersdorf , Thalheim / Erzgeb. (hence the name "Thalheimit"), Harz , Hunsrück , Black Forest , Fichtelgebirge and found in the Sauerland . In Austria it occurred in several regions of Burgenland , Carinthia , Lower Austria , Salzburg , Styria , North and East Tyrol and Upper Austria .
Other locations are Egypt , Albania , Algeria , Antarctica , Argentina , Armenia , Azerbaijan , Ethiopia , Australia , Belgium , Bolivia , Bulgaria , Burkina Faso , Burundi , Chile , China , Ecuador , El Salvador , Eritrea , Fiji , Finland , France , Georgia , Ghana , Greece , Greenland , Guatemala , Guinea , Honduras , India , Indonesia , Iran , Ireland , Italy , Japan , Cambodia , Canada , Jersey Channel Island , Kazakhstan , Kyrgyzstan , Colombia , the Democratic Republic of the Congo , Northern and South Korea , Kosovo , Cuba , Madagascar , Malaysia , Mali , Morocco , Mauritania , Mexico , Mongolia , Myanmar , Namibia , New Zealand , Niger , Nigeria , North Macedonia , Norway , Papua New Guinea , Peru , the Philippines , Poland , Portugal , Rwanda , Romania , Russia , Saudi Arabia , Sweden , Switzerland , Serbia , Zimbabwe , Slovakia , Slovenia , Spain , South Africa , Sudan , Swaziland , Tajikistan , Taiwan , Tanzania , Thaila nd , Czech Republic , Tunisia , Turkey , Ukraine , Hungary , Uzbekistan , the United Kingdom (Great Britain), the United States of America and Vietnam .
Arsenopyrite could also be detected in mineral samples from the Mid-Atlantic Ridge .
use
Arsenopyrite is the most important ore for the extraction of arsenic .
Arsenopyrite is not used as a gemstone . Occasionally suitable stones are however Hobby grinders for collectors ground .
See also
literature
- Ernestus Fridericus Glocker : Generum et Specierum Mineralium, Secundum Ordines Naturales Digestorum Synopsis, omnium, quotquot adhuc reperta sunt, mineralium nomina complectens . Eduardum Anton, Halae Saxonum (= Halle in Saxony) 1847, p. 34-43 , Ordo VI. Pyritae. Pyrite. III. Pyritae arsenopyritoidei. 10. Arsenopyrites (Latin, rruff.info [PDF; 545 kB ; accessed on August 7, 2019]).
- Petr Korbel, Milan Novák: Mineral Encyclopedia (= Villager Nature ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 48 (as arsenic gravel).
Web links
- Mineral Atlas: Arsenopyrite (Wiki)
- Arsenopyrite. In: mindat.org. Hudson Institute of Mineralogy, accessed August 7, 2019 .
- Arsenopyrite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed on August 7, 2019 .
- American-Mineralogist-Crystal-Structure-Database - Arsenopyrite. In: rruff.geo.arizona.edu. Retrieved August 7, 2019 .
Individual evidence
- ↑ a b c Hans Lüschen: The names of the stones. The mineral kingdom in the mirror of language . 2nd Edition. Ott Verlag, Thun 1979, ISBN 3-7225-6265-1 , p. 176, 276 .
- ↑ Synonyms of Arsenopyrite; other language names. In: mindat.org. Hudson Institute of Mineralogy, accessed August 7, 2019 .
- ^ Karl Hugo Strunz , Christel Tennyson : Mineralogical tables . 8th edition. Academic publishing company Geest & Portig KG, Leipzig 1982, p. 519 .
- ^ Karl Hugo Strunz , Christel Tennyson : Mineralogical tables . 8th edition. Academic publishing company Geest & Portig KG, Leipzig 1982, p. 581 .
- ↑ David Barthelmy: Arsenopyrite Mineral Data. In: webmineral.com. Retrieved August 7, 2019 .
- ^ 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. 104 (English).
- ↑ a b c d e Arsenopyrite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogyarsenopyrite.org [PDF; 61 kB ; accessed on August 7, 2019]).
- ↑ a b Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 463-465 (first edition: 1891).
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed April 25, 2019 .
- ↑ Localities for arsenopyrite. In: mindat.org. Hudson Institute of Mineralogy, accessed August 7, 2019 .