Manga time
| Manga time | |
|---|---|
| General and classification | |
| other names |
IMA 2005-021a |
| chemical formula | Al 2 [(OH) 4 | SO 4 ] • 3H 2 O |
|
Mineral class (and possibly department) |
Sulfates (and relatives) |
|
System no. to Strunz and to Dana |
7.DE.05 ( 8th edition : VI / D.06) 07/31/04/02 |
| Crystallographic Data | |
| Crystal system | triclinic |
| Crystal class ; symbol | triclinic pedial 1 or triclinic pinacoidal 1 |
| Room group (no.) | P 1 or P 1 (No. 1 or 2) |
| Lattice parameters |
a = 8.286 (5) Å ; b = 9.385 (5) Å; c = 11.35 (1) Å α = 96.1 (1) °; β = 98.9 (1) °; γ = 96.6 (1) ° |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 1 to 2 |
| Density (g / cm 3 ) | calculated: 2.15 |
| Cleavage | not observed |
| colour | colorless, white with light yellow areas |
| Line color | colorless |
| transparency | transparent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.525 n γ = 1.545 |
| Birefringence | δ = 0.020 |
| Optical character | biaxial |
Manga time is a very rarely occurring mineral from the mineral class of " sulfates " (and relatives, see classification ). It crystallizes in the triclinic crystal system with the composition Al 2 [(OH) 4 | SO 4 ] · 3H 2 O, so it is chemically a water-containing , basic aluminum sulfate.
Manga time could only be found in the form of radial aggregates with fine-needle crystals up to about 0.04 mm in size. In its pure form it is colorless and transparent, but can also appear white due to multiple refraction due to lattice construction defects or polycrystalline formation and can have light yellow zones due to foreign admixtures.
Etymology and history
Was first discovered Manga time in 2005 in the tin - silver - deposit "Mangazeisky" ( Mangazeiskoe ) about 300 km east of the Lena at Verkhoyansk in the Siberian Republic of Sakha ( Yakutia ) in Russia. The mineral was described by GM Gamyanin, Yu. Ya. Zhdanov, NV Zayakina, VF Gamyanina and VS Suknev, who named it after its type locality .
The type material of the mineral was deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences in Moscow (catalog no. 3291/1).
classification
Since the Manga period was only discovered in 2005 and recognized by the International Mineralogical Association (IMA), it is not listed in the original and since 2001 outdated system of minerals according to Strunz (8th edition). Only the "Lapis Mineralienverzeichnis", published in 2008, which, out of consideration for private collectors and institutional collections, is still based on the classic systematics of Karl Hugo Strunz , lists the mineral in the class of "sulfates, chromates, molybdates, wolframates" and there in the "Aluminit Group" with the system no. VI / D.06 and the other members Aluminite , Felsőbányait , Hydrobasaluminit , Jurbanite , Khademit , meta Aluminite , Rostit and Zaherite within the department of " Water containing sulfates with foreign anions " link.
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the IMA, assigns the Manga period to the class of "sulfates (selenates, tellurates, chromates, molybdates and wolframates)" and there into the department of "sulfates (selenates, etc.)" ) with additional anions , with H 2 O “. However, this division is further subdivided according to the relative size of the cations involved and the crystal structure. However, since the crystal structure of Manga times has not yet been defined more precisely, it is listed in the sub-section “With only medium-sized cations; unclassified ”, where he is the only member of the unnamed group 7.DE.05 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Manga period to the class of “sulfates, chromates and molybdates” and there to the “hydrous sulfates with hydroxyl or halogen” category. Here it can be found together with aluminite in the unnamed group July 31, 2004 within the subdivision of " Water-containing sulfates with hydroxyl or halogen with (A + B 2+ ) 2 (XO 4 ) Z q × x (H 2 O) ".
Education and Locations
Manga time forms as a secondary mineral in the weathering zone of heavily sericized and pyritized granodiorite . There he finds along the edges of quartz - arsenopyrite - veins usually associated with gypsum and chlorite .
Manga time could so far (as of 2012) only be proven at its type locality "Mangazeisky" in Russia.
Crystal structure
Manga time crystallizes triclinically in the space group P 1 or P 1 (space group no. 1 or 2) with the lattice parameters a = 8.286 (5) Å ; b = 9.385 (5) Å; c = 11.35 (1) Å; α = 96.1 (1) °; β = 98.9 (1) ° and γ = 96.6 (1) ° as well as 4 formula units per unit cell .
See also
literature
- GN Gamyanin, Yu. Ya. Zhdanov, NV Zayakina, VV Gamyanina, VS Suknev: Mangazeite, Al 2 (SO 4 ) (OH) 4 3H 2 O, a new mineral species , in: Proceedings of the Russian Mineralogical Society , 135 (4), p. 20 –24 (in Russian with a brief English description) and in: Geology of Ore Deposits , Volume 49, Edition 7, pp. 514-517 doi : 10.1134 / S1075701507070045
Web links
Individual evidence
- ↑ a b c Stefan Weiss: The large Lapis mineral directory. All minerals from A - Z and their properties . 5th completely revised and supplemented edition. Weise, Munich 2008, ISBN 978-3-921656-70-9 .
- ↑ a b c d e f John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols: Mangazeite , in: Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 125.8 kB )
- ↑ a b c Mindat - Manga site