Pääkkönenit
| Pääkkönenit | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA1980-063 |
| chemical formula | Sb 2 AsS 2 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.DB.05b ( 8th edition : II / D.08) 11/02/05/01 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Room group (no.) | C 2 / m (No. 12) |
| Lattice parameters |
a = 10.75 Å ; b = 3.96 Å; c = 12.49 Å β = 115.2 ° |
| Formula units | Z = 4 |
| Twinning | polysynthetic twins according to {001} |
| Physical Properties | |
| Mohs hardness | ≈ 2 (VHN 10 = 66 to 87) |
| Density (g / cm 3 ) | measured: 5.21 |
| Cleavage | in one direction |
| Break ; Tenacity | brittle |
| colour | dark gray to light gray |
| Line color | gray with a brownish tinge |
| transparency | opaque |
| shine | Metallic luster |
Pääkkönenite is a very rarely occurring mineral from the mineral class of "sulfides and sulfosalts". It crystallizes in the monoclinic crystal system with the chemical composition Sb 2 AsS 2 , so it is an antimony - arsenic - sulfide .
Pääkkönenite is opaque in every form and rarely develops well-formed crystals up to about 0.4 millimeters in size. It is mostly found in the form of irregular grains or granular mineral aggregates of light to dark gray in color and metallic sheen . His line color is also gray with a tinge of brown.
With a Mohs hardness of around 2, pääkkönenite is one of the soft minerals that, like the reference mineral gypsum, can still be scratched with a fingernail.
Etymology and history
Pääkkönenit was first discovered in the arsenic-antimony deposit Kalliosalo near Seinäjoki in western Finland and described in 1981 by Yu. S. Borodaev, NN Mozgova, NA Ozerova, NS Bortnikov, P. Oivanen and V. Iletuinen. They named the mineral after the Finnish geologist Viekko Pääkkönen (1907–1980) to honor his contributions to the exploration of ore deposits in the type region.
classification
Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the Pääkkönenite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with the molar ratio metal: S, Se, Te <1: 1", where he together with Antimonselit , Bismuthinit , Guanajuatit , Metastibnit , Ottemannit and Stibnit the unnamed group / D.08 II 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), classifies the Pääkkönenit in the category of “metal sulfides with M: S = 3: 4 and 2: 3”. This is further subdivided according to the exact molar ratio, so that the mineral can be found according to its composition in the subsection "M: S = 2: 3", where it is the only member of the unnamed group 2.DB.05b .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Pääkkönenite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here he is the only member of the unnamed group 11/02/05 within the subsection “Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 2: 3”.
Education and Locations
Pääkkönenite forms in hydrothermal ore deposits, where it is usually found in paragenesis with other arsenic and antimony-containing minerals such as arsenopyrite , lollingite , stibarsen , stibnite and vaughanite . In addition, solid antimony and arsenic, quartz , realgar , siderite and sphalerite can also occur as accompanying minerals.
So far, only about 10 sites are known for Pääkkönenite, whereby its type locality Kalliosalo near Seinäjoki is the only site in Finland so far.
Other previously known sites are the "Golden Giant Mine" near Marathon in the Canadian province of Ontario, a kermesite site (unnamed antimony mine) near Dafeng near Shanglin in China, Příbram in the Czech region of Bohemia, and the "Matra mine" in the French Municipality of Moïta (Haute-Corse), the “Plaka Mines” near Lavrio in the Greek region of Attica and the “Cryo-Genie Mine” near Warner Springs in San Diego County (California) in the United States of America (USA).
Crystal structure
Pääkkönenit crystallizes monoclinically in the space group C 2 / m (space group no. 12) with the lattice parameters a = 10.75 Å ; b = 3.96 Å; c = 12.49 Å and β = 115.2 ° as well as four formula units per unit cell .
See also
literature
- Yu. S. Borodaev, NN Mozgova, NA Ozerova, NS Bortnikov, P. Oivanen, V. Iletuinen: Pääkkonenite, Sb 2 AsS 2 , a new mineral from the Seinäjoki ore region in Finland. In: Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva. Volume 110, Chapter 4 (1981), pp. 480-487 ( PDF 660.7 kB , Russian)
- Michael Fleischer, GY Chao, JA Mandarino: New mineral names. In: American Mineralogist. Volume 67 (1982), pp. 854-860 ( PDF 589.7 kB )
- P. Bonazzi, D. Borrini, F. Mazzi, F. Olmi: Crystal structure and twinning of Sb 2 AsS 2 , the synthetic analogue of pääkkönenite. In: American Mineralogist. Volume 80 (1995), pp. 1054-1058 ( PDF 618.6 kB )
Web links
Individual evidence
- ↑ Mindat - Pääkkönenite
- ↑ a b c d e 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. 96 .
- ↑ Webmineral - Pääkkönenite
- ↑ a b c Pääkkönenite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 63.2 kB )
- ↑ Find location list for Pääkkönenite at the Mineralienatlas and at Mindat