Yofortierite
| Yofortierite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | Mn 2+ 5 [(OH) 2 | Si 8 O 20 ] • 7H 2 O |
|
Mineral class (and possibly department) |
Silicates and germanates - layered silicates (phyllosilicates) |
|
System no. to Strunz and to Dana |
9.EE.20 ( 8th edition : VIII / H.33) 74.03.01a.03 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Room group (no.) | C 2 / m (No. 12) |
| Lattice parameters |
a = 14.1686 Å ; b = 17.8583 Å; c = 5.2919 Å β = 105.878 ° |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 2.5 |
| Density (g / cm 3 ) | measured: 2.18; calculated: [2.82] |
| Cleavage | no; elastic |
| colour | pink to purple, beige, reddish to orange-brown, dark brown, bronze colors |
| Line color | light pink |
| transparency | transparent to opaque |
| shine | Silky gloss |
| Crystal optics | |
| Refractive indices | n α = - |
| Birefringence | δ = 0.029 |
| Optical character | biaxial |
Yofortierite is a very rarely occurring mineral from the mineral class of "silicates and germanates". It crystallizes in the monoclinic crystal system with the chemical composition of Mn 2+ 5 [(OH) 2 | Si 8 O 20 ] · 7H 2 O, is thus a water-containing manganese - silicate with additional hydroxide . Structurally yofortierite belongs to the layered silicates (phyllosilicates).
Yofortierite develops fibrous to needle-like crystals , which are usually arranged in radial, tufted or spherical aggregates and show a silk-like sheen . The mineral comes in different colors from pink to purple, reddish to orange-brown and beige to dark brown or bronze colors. However, his line color is always light pink.
Etymology and history
Yofortierite was first discovered on Mont Saint-Hilaire in the Canadian province of Québec and described in 1975 by Guy Perrault, Yves Harvey and Raymond Pertsowsky, who named the mineral after the then director of the Geological Survey of Canada, Yves Oscar Fortier .
Type material of the mineral is found in the École polytechnique de Montréal (Catalog No. 13017), the Royal Ontario Museum in Toronto (Catalog No. M33627), and the Canadian Museum of Nature in Ottawa, Canada; in the National Museum of Natural History in Washington, DC, USA (Catalog No. 131952); in the Natural History Museum in London, England (catalog no. 1975,418) and in the University of Paris , in the Muséum national d'histoire naturelle and the Mines ParisTech ( École des mines ) in Paris, France.
classification
Already in the outdated but still partially in use 8th edition of the mineral classification by Strunz of Yofortierit belonged to the mineral class of "silicates and Germanates" and then to the Department of "phyllosilicates (phyllosilicates)" where he collaborated with Falcondoit , Kalifersit , Loughlinit , palygorskite , Sepiolite and Tuperssuatsiait the "Palygorskitgruppe" with the system no. VIII / H.33 .
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 classifies yofortierite in the “phyllosilicates” department. This is, however, further subdivided according to the structure of the layers, so that the mineral, according to its structure, can be found in the sub-section “Simple tetrahedral networks of 6-membered rings, connected by octahedral networks or bands”, where it can only be found together with palygorskite and Tuperssuatsiait the "Palygorskitgruppe" with the system no. with the system no. 9.EE.20 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns yofortierite to the class of "silicates and Germanates" and there in the department of "layered silicates: modulated layers". Here it is together with palygorskite, tuperssuatsiaite and califersite in the "palygorskite sepiolite group (palygorskite subgroup)" with system no. 74.03.01a can be found in the subsection " Layered Silicates: Modulated Layers with Connected Stripes ".
Education and Locations
Yofortierit formed in the late phase of hydrothermal processes in pegmatite - veins within nepheline - syenites . As Begleitminerale occur among other Aegirin , albite , analcime , Eudialyt , microcline , Polylithionit and Serandit on.
In addition to its type locality Mont Saint-Hilaire, more precisely in the Poudrette quarry, the mineral has only been found in Canada in the Demix-Varennes quarry between Saint-Amable and Varennes in the province of Québec.
Yofortierite was also found at Kvanefjeld near Narsaq in southern Greenland, in the quarries near Aris in the Windhoek district in Namibia, in a natrolite stock on Mount Karnassurt in the Lowosero-Tundra massif (Murmansk Oblast) on the Russian Kola peninsula and in the Jones Mill quarry at Magnet Cove in Hot Spring County of the US state Arkansas.
Crystal structure
Yofortierite crystallizes monoclinically in the space group C 2 / m (space group no. 12) with the lattice parameters a = 14.1686 Å ; b = 17.8583 Å; c = 5.2919 Å and β = 105.878 ° as well as four formula units per unit cell .
See also
literature
- Guy Perrault, Yves Harvey, Raymond Pertsowsky: La yofortierite, un nouveau silicate hydraté de manganése de St-Hilaire, PQ In: The Canadian Mineralogist. Volume 13 (1975), pp. 68-74 ( PDF 1 MB )
- Michael Fleischer , George Y. Chao, JA Mandarino: New mineral names. In: American Mineralogist. Volume 61 (1976), pp. 338–341 ( PDF 529.5 kB ; yofortierite from p. 4)
- 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. 681 .
Web links
- Mineral Atlas: Yofortierite (Wiki)
- Web mineral - Yofortierite
- Database-of-Raman-spectroscopy - Yofortierite
- American-Mineralogist-Crystal-Structure-Database - Yofortierite
Individual evidence
- ↑ a b IMA / CNMNC List of Mineral Names; March 2014 (PDF 1.5 MB)
- ↑ a b c Frank C. Hawthorne, Yassir A. Abdu, Kimberly T. Tait, Malcom E. Back: The crystal structure of yofortierite. In: The Canadian Mineralogist. Volume 51 (2013), pp. 243-251 doi : 10.3749 / canmin.51.2.243
- ↑ a b Yofortierite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 77.6 kB )
- ^ Mindat - Yofortierite
- ↑ Find location list for yofortierite at the Mineralienatlas and at Mindat