Bustamit
| Bustamit | |
|---|---|
 (size: 7 × 5 cm) |
|
| General and classification | |
| chemical formula | Ca 3 (Mn, Ca) 3 [Si 3 O 9 ] 2 |
|
Mineral class (and possibly department) |
Silicates and germanates - chain and band silicates |
|
System no. to Strunz and to Dana |
9.DG.05 ( 8th edition : VIII / F.18) 65.02.01.02 |
| Similar minerals | Wollastonite |
| Crystallographic Data | |
| Crystal system | triclinic |
| Crystal class ; symbol | triclinic pinacoidal; 1 |
| Space group | P 1 (No. 2) |
| Lattice parameters |
a = 7.74 Å ; b = 7.16 Å; c = 13.82 Å α = 90.5 °; β = 94.6 °; γ = 103.9 ° |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 5.5 to 6.5 |
| Density (g / cm 3 ) | measured: 3.32 to 3.43; calculated: 3.421 |
| Cleavage | completely after {100} good after {110} and {1 1 0} indistinct after {010} |
| Break ; Tenacity | uneven to scalloped |
| colour | pink to red-brown |
| Line color | White |
| transparency | transparent to translucent |
| shine | Glass gloss to matt |
| Crystal optics | |
| Refractive indices |
n α = 1.640 to 1.695 n β = 1.651 to 1.708 n γ = 1.653 to 1.710 |
| Birefringence | δ = 0.013 to 0.015 |
| Optical character | biaxial negative |
| Pleochroism | visible: X = Z = orange; Y = pink |
| Other properties | |
| Special features | pink to magenta fluorescence by UV light irradiation |
The mineral bustamite is a rarely occurring chain silicate from the wollastonite group. It crystallizes in the triclinic crystal system with the chemical composition Ca 3 (Mn, Ca) 3 [Si 3 O 9 ] 2 and develops mostly prismatic to tabular or needle-like crystals , but also fibrous to massive mineral aggregates from pink to red-brown in color with white streak color .
Etymology and history
Bustamit was first discovered in the " Franklin Mine" in Sussex County in the US state of New Jersey. The mineral was first described in 1826 by Alexandre Brongniart . The namesake is only given imprecisely in his publication:
«Nous la désignons par le nom de BUSTAMITE, qui rappelle le minéralogiste de Mexico qui nous l'a fait connaître. »
"We call it the name Bustamite, which is reminiscent of the mineralogist from Mexico through whom we got to know it."
Brongniart may have wanted to honor the Mexican biologist and mineralogist Miguel Bustamante y Septiem (1790-1844) with his name .
According to other sources, the namesake is said to be the physician, general and three-time President of Mexico Anastasio Bustamante (1780-1853).
classification
In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the bustamite belonged to the mineral class of "silicates and germanates" and there to the department of " chain silicates and band silicates (inosilicates)", where together with cascandite , denisovite , ferrobustamite , Foshagite , Jennit , Pectolite , Serandite , Vistepit , wollastonite-1A and wollastonite-2M formed a separate group.
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 Bustamit to the class of "silicates and germanates" and there in the department of "chain and band silicates (inosilicates)" a. This department is, however, further subdivided according to the type of chain formation, so that the mineral can be found in the subdivision “Chain and band silicates with 3-periodic single and multiple chains”, where it can be found together with cascandite, ferrobustamite, pectolite , Sérandite, Tanohataite, wollastonite-1A, wollastonite-2M in the "wollastonite group" with the system no. 9.DG.05 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Bustamit to the class of "silicates and Germanates" and there in the department of "chain silicate minerals". Here it is also together with wollastonite-1A, wollastonite-2M, wollastonite-3A-4A-5A-7A, ferrobustamite, pectolite, serandite, cascandite, denisovite and tanohataite in the "wollastonite group" with the system no. 65.02.01 to be found in the subsection " Chain Silicates: Simple unbranched chains, W = 1 with chains P = 3 ".
Crystal structure
Bustamit crystallizes triclinic in the space group P 1 (space group no. 2) with the lattice parameters a = 7.74 Å ; b = 7.16 Å; c = 13.82 Å; α = 90.5 °; β = 94.6 ° and γ = 103.9 ° as well as 2 formula units per unit cell .
properties
Under long-wave UV light , some bustamites show a pink to magenta fluorescence , similar to that of neon-colored highlighters .
Education and Locations
(size: 9.1 × 7.8 × 5.7 cm)
Bustamit is formed in skarn by metamorphosis or in manganese-rich hydrothermal solutions . Accompanying minerals include Braunite , Calcite , Diopside , Glaukochroit , Johannsenite , Rhodonite , Tephroit , Garnet and Wollastonite .
Overall, Bustamit has so far (as of 2011) been found at around 75 sites. In addition to the type locality "Franklin Mine", the mineral was also found in the USA in the "Sterling Mine" near Ogdensburg (New Jersey) ; with Agnew Meadows in Madera County and Inyo County , California; Terryall in Park County , Colorado; Hanover in Grant County (New Mexico) and on Lake Crescent and Mount Jupiter in Jefferson County (Washington) .
In Germany, the mineral was found near Mendig and Kruft in the Eifel (Rhineland-Palatinate) and near Elbingerode in the Harz (Saxony-Anhalt).
In Austria, Bustamit has only performed on Mooserboden in the Kaprun valley in Salzburg.
Other locations are Argentina , Australia , Bulgaria , China , France , Honduras , Italy , Japan , Mexico , Mongolia , Namibia , New Zealand , Norway , Peru , Romania , Russia , Sweden , Spain , South Africa , Turkey and the United Kingdom (Great Britain).
use
Bustamite contains a relatively high amount of manganese with a proportion of up to 32.4% , but it is too rare to be used as ore . Occasionally, however, it is cut into gemstones for interested collectors .
See also
literature
- Alexandre Brongniart: Sur la bustamite, bisilicate de manganèse et de chaux du Mexique . In: Anneles des Sciences Naturelles . tape 8 , no. 4 , 1826, pp. 411-418 ( rruff.info [PDF; 471 kB ; accessed on March 9, 2018]).
Web links
- Mineral Atlas: Bustamite (Wiki)
- realgems.org - Bustamit (with picture examples of cut stones)
Individual evidence
- ↑ a b c d e Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 636 .
- ↑ a b Webmineral - Bustamite (English)
- ↑ a b c Bustamite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 76 kB ; accessed on March 9, 2018]).
- ↑ a b c d e f g h Mindat - Bustamite (English)
- ↑ Type locality Franklin Mine, Franklin, Sussex County, New Jersey, USA in the Mineralienatlas and Mindat
- ^ Alexandre Brongniart: Sur la bustamite, bisilicate de manganèse et de chaux du Mexique . In: Anneles des Sciences Naturelles . tape 8 , no. 4 , 1826, pp. 418 ( rruff.info [PDF; 471 kB ; accessed on March 9, 2018]).
- ↑ Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason , Abraham Rosenzweig: Dana's New Mineralogy . 8th edition. John Wiley & Sons, New York (et al.) 1997, ISBN 0-471-19310-0 , pp. 1318 .
- ^ Walter Schumann: Precious stones and gemstones. All kinds and varieties. 1900 unique pieces . 16th revised edition. BLV Verlag, Munich 2014, ISBN 978-3-8354-1171-5 , pp. 238 .