Planerite
| Planerite | |
|---|---|
 |
|
| General and classification | |
| chemical formula | □ Al 6 [(OH) 8 | (PO 4 ) 2 | (PO 3 OH) 2 ] • 4H 2 O |
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.DD.15 ( 8th edition : VII / D.15) 09/22/03/06 |
| Crystallographic Data | |
| Crystal system | triclinic |
| Crystal class ; symbol | triclinic pinacoidal; 1 |
| Room group (no.) | P 1 (No. 2) |
| Lattice parameters |
a = 7.65 Å ; b = 10.15 Å; c = 7.65 Å, α = 111.9 °; β = 115.9 °; γ = 67.6 ° |
| Formula units | Z = 1 |
| Physical Properties | |
| Mohs hardness | 5 |
| Density (g / cm 3 ) | measured: 2.65 to 2.68; calculated: 2.71 |
| Cleavage | not observed |
| Break ; Tenacity | splintery; brittle |
| colour | white, light green, blue green, olive green |
| Line color | greenish white |
| transparency | opaque, translucent edges |
| shine | matt, chalky, earthy |
Planerite is a rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the triclinic crystal system with the chemical composition □ Al 6 [(OH) 8 | (PO 4 ) 2 | (PO 3 OH) 2 ] · 4H 2 O, so it is a water-containing aluminum phosphate with additional hydroxide ions . The symbol □ indicates that this structure space is not fully occupied.
Planerite is a member of the "turquoise group" and forms a mixed crystal row with turquoise (CuAl 6 [(OH) 2 | PO 4 ] · 4H 2 O) .
The mineral only develops microscopic crystals that form either spherical or kidney-shaped mineral aggregates or crusty coatings. It is generally opaque and only translucent along thin edges. Fresh samples are initially light green to almost white, but in the air they darken to blue-green or olive-green over time.
Special properties
When heated, planerite turns gray and "decrepitated" (also decrepitation , crackling ), ie the water of crystallization it contains escapes with a crackling noise and the mineral atomises or breaks into small particles.
The mineral is relatively insensitive to acids , but it decomposes easily when boiled in caustic soda .
Etymology and history
Planerite was first discovered in the copper mine near Gumeschewsk in the Urals (Russia) and described in 1862 by Hans Rudoph Hermann , who named the mineral after its discoverer, the Russian mineralogist and director of the Gumechewsk copper works, Dimitrii Ivanovich Planer (1821-1882).
classification
Already in the now outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the planerite belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the department of "water-containing phosphates with foreign anions ", where together with aheylite and chalcosiderite , Faustit and turquoise the "turquoise group" with the system no. VII / D.15 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 the planerite 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 according to its composition in the sub-section “With exclusively medium-sized cations; (OH etc.): RO 4 = 2: 1 "can be found, where the" turquoise group "with the system no. Is also found together with aheylite, chalcosiderite, Faustite and turquoise. 8.DD.15 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the planerite to the class of "phosphates, arsenates and vanadates" and there to the category of "water-containing phosphates, etc., with hydroxyl or halogen". Here it is in the " turquoise group " with the system no. 42.09.03 within the subsection "Water-containing phosphates etc., with hydroxyl or halogen with (A) 3 (XO 4 ) 2 Z q × x (H 2 O)".
Education and Locations
Planerite forms secondarily in phosphate-rich aluminum deposits . As accessory mineral may include quartz , Wavellite , Variscit and metavariscite occur.
As a rare mineral formation, planerite could only be detected at a few sites, whereby so far (as of 2013) around 40 sites are known. In addition to its type locality in Gumeschewsk, the mineral was also found in Russia on Chernovskaya Mountain in Sverdlovsk Oblast and in the Temir quarry near Chebarkul in Chelyabinsk Oblast in the Urals and in the Këster deposit in the Arga-Ynnakh-Khai granite massif in the Russian Republic of Sakha (Yakutia ) being found.
In Germany, Planerit is known from the “Mark” mine near Essershausen and the “Rotlaufchen” mine near Waldgirmes in Hesse, from the Hardtkopf near Linnepe , from the Föckinghausen quarry (Bestwig) and from the David mine near Warstein in North Rhine-Westphalia and from the Lichtenberg waste dump near Ronneburg in Thuringia.
Other previously known sites are in Australia, Burundi, France, Ireland, Italy, Japan, the Democratic Republic of the Congo (Zaire), New Zealand, Portugal, Romania, Spain, South Africa, the Czech Republic and the United States of America (USA).
Crystal structure
Planerite crystallizes triclinically in the space group P 1 (space group no. 2) with the lattice parameters a = 7.65 Å ; b = 10.15 Å; c = 7.65 Å; α = 111.9 °; β = 115.9 ° and γ = 67.6 ° as well as one formula unit per unit cell .
See also
literature
- R. Hermann: Investigations of some new Russian minerals. 1. About planerite, a new mineral , In: Bulletin de la Société Impériale des Naturalistes de Moscou , Volume 35 (1862), pp. 240–243 ( PDF 194.4 kB )
- Eugene E. Foord, Joseph E. Taggart, jr .: A reexamination of the turquoise group: the mineral aheylite, planerite (redefined), turquoise and coeruleolactite , In: Mineralogical Magazine , Volume 62 (1998), pp. 93–111 ( PDF 1.13 MB )
Web links
- Mineral Atlas: Planerit (Wiki)
Individual evidence
- ↑ a b c d e f 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. 503, 504 .
- ↑ Webmineral - Planerite
- ↑ a b Planerite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 66.6 kB )
- ↑ a b R. Hermann: Investigations of some new Russian minerals. 1. About planerite, a new mineral , In: Bulletin de la Société Impériale des Naturalistes de Moscou , Volume 35 (1862), p. 241 ( PDF 194.4 kB )
- ^ Mindat - Planerite
- ↑ Mindat - Number of locations for Planerit
- ↑ List of locations for Planerite in the Mineralienatlas and Mindat