Mozartite
| Mozartite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1991-016 |
| chemical formula | CaMn [OH | SiO 4 ] |
|
Mineral class (and possibly department) |
Silicates and Germanates - island silicates |
|
System no. to Strunz and to Dana |
9.AG.60 ( 8th edition : VIII / B.23) April 52, 02.01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-disphenoidic; 222 |
| Space group | P 2 1 2 1 2 1 (No. 19) |
| Lattice parameters | a = 7.22 Å ; b = 8.69 Å; c = 5.84 Å |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | not defined; 6th |
| Density (g / cm 3 ) | measured: 3.63 (4); calculated: 3.68 |
| Cleavage | Please complete |
| Break ; Tenacity | clamshell; brittle |
| colour | reddish brown to deep red |
| Line color | red |
| transparency | transparent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.840 (5) n β = 1.855 (5) n γ = 1.920 (5) |
| Birefringence | δ = 0.080 |
| Optical character | biaxial positive |
| Axis angle | 2V = measured: 50 ° to 52.8 °; calculated: 54 ° |
| Pleochroism | Strong: X = yellow-brown, Y = yellow, Z = red-orange |
Mozartite is an extremely rare mineral from the mineral class of "silicates and germanates". It crystallizes in the orthorhombic crystal system with the chemical composition CaMn [OH | SiO 4 ] and is therefore chemically a calcium - manganese - silicate with additional hydroxide ions . Structurally , Mozartite is one of the island silicates .
Mozartite seldom develops hypidiomorphic (partially shaped) short prismatic crystals stretched along the a-axis, slightly more than four centimeters long with a glass-like sheen on the surfaces. It is mostly found in the form of granular mineral aggregates and inclusions in other minerals. The transparent crystals are reddish-brown to deep red in color and also leave a red line on the marking board .
Etymology and history
Was first discovered in 1991 Mozartit mine "Cerchiara" ( Cerchiara Mine ) in Val di Vara (German Vara Valley ) near the municipalities of Borghetto di Vara and Pignone in the northern Italian region of Liguria . The mineral was scientifically described and published for the first time in 1993 by Riccardo Basso , Gabriella Lucchetti , Livio Zefiro and Andrea Palenzona , who named it after the outstanding musician and composer Wolfgang Amadeus Mozart (1756–1791).
The reason for the unconventional choice of the name was that the mineral was discovered in the 200th year of death of the musician and, according to the mineralogist Alfred Whittaker, a close connection between the geological and mineralogical sciences and Mozart's music - especially with his last opera The Magic Flute - exist. The opera was composed at a time when geology developed from mineralogy, chemistry from alchemy, astronomy from astrology and mathematics from numerology. Little is known about Mozart's collaboration with the scientists of his time, especially with the mineralogists Ignaz von Born and Sir Carl Ludwig Giesecke .
The type material of the mineral is kept at the University of Genoa in Italy.
classification
Already in the outdated, but partly still in use 8th edition of the mineral systematics according to Strunz , the mozartite belonged to the mineral class of "silicates and germanates" and there to the department of "island silicates with non-tetrahedral anions (Neso-subsilicates)", where together with cebollite , Chantalit and Vuagnatit formed the unnamed group VIII / B.23 .
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 Mozartite in the category of "island silicates (nesosilicates)". This is further subdivided according to the possible presence of additional anions and the coordination of the cations involved , so that the mineral is classified according to its composition in the sub-section “Island silicates with additional anions; Cations can be found in mostly [6] er and> [6] er coordination ”, where the“ Vuagnatite group ”with the system no. 9.AG.60 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Mozartite to the class of "silicates and Germanates" and there in the department of "island silicates: SiO 4 groups and O, OH, F and H 2 O". And here he is together with Vuagnatit in the " Vuagnatit group " with the system no. 52.04.02 within the subsection “ Island silicates: SiO 4 groups and O, OH, F and H 2 O with cations in [6] and / or> [6] coordination”.
Crystal structure
Mozartite crystallizes orthorhombically in the space group P 2 1 2 1 2 1 (space group no. 19) with the lattice parameters a = 7.22 Å ; b = 8.69 Å and c = 5.84 Å as well as 4 formula units per unit cell .
Education and Locations
Mozartite is formed in the metamorphosed manganese deposits . The accompanying minerals include calcite , hausmannite , pectolite and quartz .
Mozartite is one of the very rare mineral formations, of which only a few samples exist so far, which have been collected at four known sites so far (as of 2015). In addition to its type locality Cerchiara Mine in Italy, the mineral is also known from the Kamisugai mine in the prefecture of Ehime on the Japanese island of Shikoku as well as the Wessels mine near Hotazel and the N'Chwaning II mine near Kuruman in the manganese fields of the Kalahari in the South African province of Northern Cape .
See also
literature
- Riccardo Basso, Gabriella Lucchetti, Livio Zefiro, Andrea Palenzona: Mozartite, CaMn (OH) SiO 4 , a new mineral species from the Cerchiara Mine, Northern Apennines, Italy. In: The Canadian Mineralogist. Volume 31 (1993), pp. 331–336 ( PDF 484.2 kB )
Web links
- Mineral Atlas: Mozartite (Wiki)
- Database-of-Raman-spectroscopy - Mozartite
- American-Mineralogist-Crystal-Structure-Database - Mozartite
Individual evidence
- ↑ a b c d 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. 557 .
- ↑ a b c d Mozartite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 69.3 kB )
- ↑ a b c d e f g Mindat - Mozartite
- ↑ Webmineral - Mozartite
- ↑ Riccardo Basso, Gabriella Lucchetti, Livio Zefiro, Andrea Palenzona: Mozartite, CaMn (OH) SiO 4 , a new mineral species from the Cerchiara Mine, Northern Apennines, Italy. In: The Canadian Mineralogist. Volume 31 (1993), pp. 331–336 ( PDF 484.2 kB )
- ^ Alfred Whittaker: Mineralogy and Magic Flute. In: Communications of the Austrian Mineralogical Society, Volume 143 (1998), pp. 107-134 ( PDF 655.1 kB )
- ↑ Find location list for Mozartite in the Mineralienatlas and Mindat