Greifensteinite
| Greifensteinite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 2001-044 |
| chemical formula |
|
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.DA.10 ( 8th edition : VII / D.01) July 42, 07.03 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | C 2 / c (No. 15) |
| Lattice parameters |
a = 15.903 Å ; b = 11.885 Å; c = 6.677 Å β = 94.68 ° |
| Formula units | Z = 4 |
| Frequent crystal faces | {100}, {110} |
| Physical Properties | |
| Mohs hardness | 4.5 |
| Density (g / cm 3 ) | measured: 2.93 (2); calculated: 2.95 (2) |
| Cleavage | no; Secretions after {100} |
| Break ; Tenacity | uneven; brittle |
| colour | dark olive green |
| Line color | White |
| transparency | transparent to translucent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.624 (2) n β = 1.634 (2) n γ = 1.638 (2) |
| Optical character | biaxial negative |
| Pleochroism | visible: X = light bluish green; Y = light green; Z = brownish green |
Greifensteinite is a rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the monoclinic crystal system with the idealized chemical composition Ca 2 Be 4 Fe 2+ 5 (PO 4 ) 6 (OH) 4 · 6H 2 O, so it is chemically a water-containing calcium - beryllium - iron phosphate with additional hydroxide ions .
Greifensteinite the iron analog of is Roscherit (Ca 2 Mn 2+ 5 Be 4 (PO 4 ) 6 (OH) 4 · 6H 2 O) and zanazziite (Ca 2 Be 4 Mg 5 (PO 4 ) 6 (OH) 4 · 6H 2 O).
The mineral is transparent to translucent and only develops small, prismatic crystals of a dark olive-green color, which are mostly arranged in radial aggregates .
Etymology and history
Greifensteinite was first discovered on the rock formation known as Greifensteine in the Saxon Ore Mountains and described in 2002 by NV Chukanov, S. Möckel, RK Rastsvetaeva and AE Zadov, who named the mineral after its type locality .
The type material of the mineral was deposited in the Museum of Mineralogy and Geology Dresden .
classification
In the 8th edition of the mineral systematics according to Strunz , which is now outdated, but still in use , the Greifensteinite belonged to the department of "Water-containing phosphates with foreign anions ", where together with Atencioite , Bearsite , Glucin , Guimarãesite , Moraesite , Roscherite , Ruifranconite , Uralolite , Weinebeneit and Zanazziit formed the unnamed group VII / D.01 .
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 Greifensteinite 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 , so that the mineral can be found according to its composition in the sub-section “With small (and occasionally larger) cations”, where it is found together with Atencioit, Footemineit , Guimarãesit, Roscherite, Ruifrancoit and Zanazziit the "Roscheritgruppe" with the system no. 8.DA.10 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Greifensteinite to the class of "phosphates, arsenates and vanadates" and there to the category of "water-containing phosphates, etc., with hydroxyl or halogen". Here he is together with Atencioit, Footemineit, Guimarãesit, Roscherit, Ruifrancoit and Zanazziit in the " Roscherite group " with the system no. July 42, 2007 within the subsection “Phosphates containing water, etc., with hydroxyl or halogen with (AB) 5 (XO 4 ) 3 Z q × x (H 2 O)”.
Crystal structure
Greifensteinite crystallizes monoclinically in the space group C 2 / c (space group no. 15) with the lattice parameters a = 15.903 Å ; b = 11.885 Å; c = 6.677 Å and β = 94.68 ° and 4 formula units per unit cell .
Education and Locations
Greifensteinite forms in miarolithischen cavities of lithium-rich granite - pegmatites . The accompanying minerals include albite , apatite , childrenite , elbaite , herderite , potassium feldspar , montmorillonite , quartz , roscherite and viitaniemiite .
As a rare mineral formation, Greifenstein could only be detected at a few sites, whereby so far (as of 2013) around 20 sites are known. Its type locality Greifenstein is the only known site in Germany so far.
In Austria, too, only one site is known to date. There the mineral was discovered in an exploration tunnel for the extraction of the lithium mineral spodumene on the Brandrücke in the Weinebene Alpine pass (Carinthia) (see also Mining in Carinthia ).
Furthermore, Greifensteinit occurred in several places in the river valleys of the Rio Doce and the Rio Jequitinhonha in the Brazilian state of Minas Gerais , in the deposit "Ungursai Ta" on the Irtysh in eastern Kazakhstan and in several places in the US states of Maine and New Hampshire and in the Tip Top Mine near Custer , South Dakota.
See also
literature
- NV Chukanov, S. Möckel, RK Rastsvetaeva, AE Zadov: Greifensteinite Ca 2 Be 4 (Fe 2+ , Mn) 5 (PO 4 ) 6 (OH) 4 6H 2 O - a new mineral from Greifenstein, Saxony . In: Zapiski Vserossijskogo Mineralogicheskogo Obshchestva . tape 131 , no. 4 , 2002, p. 47–52 ( rruff.info [PDF; 297 kB ; accessed on November 11, 2017] in Russian with an English summary).
- RK Rastsvetaeva, OA Gurbanova, NV Chukanov: Crystal structure of cross range Destinite Ca 2 Be 4 (Fe 2+ , Mn) 5 (PO 4 ) 6 (OH) 4 · 6H 2 O . In: Doklady Chemistry . tape 383 , no. 1–3 , 2002, pp. 78-81 , doi : 10.1023 / A: 1014787408843 .
- Edward S. Grew, Nikolai N. Pertsev, Andrew C. Roberts: New mineral names . In: American Mineralogist . tape 88 , 2003, p. 1175–1180 ( rruff.info [PDF; 313 kB ; accessed on November 11, 2017]).
Web links
- Mineral Atlas: Greifensteinite (Wiki)
- Mindat - Greifensteinite
- Database-of-Raman-spectroscopy - Greifensteinite
- American-Mineralogist-Crystal-Structure-Database - Greifensteinite
Individual evidence
- ↑ a b c IMA / CNMNC List of Mineral Names; February 2013 (PDF 1.3 MB)
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .
- ↑ Webmineral - Greifensteinite
- ↑ a b c American-Mineralogist-Crystal-Structure-Database - Greifensteinite
- ^ Joseph A. Mandarino: New minerals . In: The Canadian Mineralogist . tape 42 , 2004, p. 215–234 ( rruff.info [PDF; 513 kB ; accessed on November 11, 2017]).
- ↑ Mindat - Number of localities for Greifensteinit
- ↑ Find location list for Greifensteinit at the Mineralienatlas and at Mindat