Hechtsbergite
| Hechtsbergite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1995-050 |
| chemical formula |
|
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.BO.15 11.11.06.02 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 1 / c (No. 14) |
| Lattice parameters |
a = 6.791 (1) Å ; b = 7.535 (1) Å; c = 10.881 (1) Å β = 107.00 (1) ° |
| Frequent crystal faces | {111}, {112}, {113}, { 1 01}, { 1 02}, { 3 02} |
| Physical Properties | |
| Mohs hardness | 4.5 ( VHN 15 = 320) |
| Density (g / cm 3 ) | calculated: 6.87 |
| Cleavage | is missing |
| Break ; Tenacity | shell-like |
| colour | brown |
| Line color | yellow |
| transparency | transparent to translucent |
| shine | Diamond luster |
| Crystal optics | |
| Refractive indices |
n α = 2.260 n β = 2.270 n γ = 2.300 |
| Birefringence | δ = 0.040 |
| Optical character | biaxial positive |
| Other properties | |
| Chemical behavior | soluble in dilute hydrochloric acid |
Hechtsbergit is a very rarely occurring minerals from the mineral class of "phosphates, arsenates, and vanadates" with the chemical composition of Bi 2 [O | OH | VO 4 ] and is therefore chemically seen a bismuth - vanadate with additional oxygen - and hydroxide ions .
Hechtsbergite crystallizes in the monoclinic crystal system , but develops only tiny, idiomorphic crystals and mineral aggregates up to about 0.2 mm in diameter. The mineral is brown in color, but leaves a yellow line on the marking board . The surfaces of the transparent to translucent crystals have a diamond-like sheen .
Etymology and history
Hechstbergite was first discovered in the Hechtsberg quarry of the same name near Hausach in the Ortenau district of Baden-Württemberg. The analysis and initial description was carried out by Werner Krause, Heinz J. Bernhardt, G. Blass, H. Effenberger, H.-W. Graf, who named the mineral according to its type locality and submitted their results and the chosen name to the International Mineralogical Association (IMA) for examination in 1995 (IMA's internal entry number: 1995-050 ). After being recognized as an independent mineral species, the first description of the hechtsbergite was published in 1997 in the science magazine Neues Jahrbuch für Mineralogie, Monatshefte .
The type material of the mineral is kept in the Mineralogical Institute of the Ruhr University Bochum .
classification
Since the hechtsbergite was only recognized as an independent mineral in 1995, it is not yet listed in the 8th edition of the Strunz mineral classification, which has been outdated since 1977 . Only in the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this old form of Karl Hugo Strunz's system , was the mineral given the system and mineral number. VII / B.30-03 . In the "lapis system" this corresponds to the class of "phosphates, arsenates and vanadates" and there the department "anhydrous phosphates, with foreign anions F, Cl, O, OH", where hechtsbergite together with atelestite , petitjeanite , priceingerite , Schlegelite , Schumacherit and Smrkovecit form an independent but unnamed group (as of 2018).
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and was updated by the IMA until 2009, also assigns hechtsbergite to the category of “phosphates, etc. with additional anions; without H 2 O “. However, this is further subdivided according to the relative size of the cations involved and the molar ratio of the additional anions (OH etc.) to the phosphate, arsenate or vanadate complex (RO 4 ), so that the mineral is classified in the subsection “With only large Cations; (OH, etc.): RO 4 ≥ 1: 1 "can be found, where only together with atelestite and smrkovecite the" atelestite group "with the system no. 8.BO.15 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns hechtsbergite to the class of "phosphates, arsenates and vanadates" and there to the category of "anhydrous phosphates, etc., with hydroxyl or halogen". Here he is together with Smrkovecit in the " Smrkovecit group " with the system no. 41.11.06 within the subsection "Anhydrous phosphates etc., with hydroxyl or halogen with different formulas".
Chemism
The electron beam microanalysis showed an average composition of 83.02% by weight Bi 2 O 3 , 15.18% by weight V 2 O 5 , 0.52% by weight As 2 O 5 and 1.59% by weight H 2 O (calculated).
On the basis of 6 oxygen atoms , the empirical formula Bi 2.03 O 1.08 (OH) 1.01 (VO 4 ) 0.95 (AsO 4 ) 0.03 was calculated and becomes Bi 2 O (OH) (VO 4 ) idealized.
Crystal structure
Hechtsbergite crystallizes monoclinically in the space group P 2 1 / c (space group no. 14) with the lattice parameters a = 6.791 (1) Å ; b = 7.535 (1) Å; c = 10.881 (1) Å and β = 107.00 (1) ° as well as 4 formula units per unit cell .
properties
With a Mohs hardness of 4.5, hechtsbergite is one of the medium-hard minerals that, like the reference minerals fluorite (hardness 4) and apatite (hardness 5), can be scratched with a pocket knife . Hechtsbergite has no cleavage and breaks like glass like mussels.
Due to the small sample sizes of the mineral, its density could only be determined mathematically using the crystal data obtained. For hechtsbergite it is 6.87 g / cm 3 .
Hechtsbergite is easily soluble in dilute hydrochloric acid.
Education and Locations
Hechtsbergite formed in tiny cavities in gneiss , which is mined as a road surface at its type locality in the Hechtsberg quarry near Hausach . As accompanying minerals may include Beyerit , Bismutit , chrysocolla , Eulytin , Klinobisvanit , Mixit , Namibit and Waylandite occur.
As a very rare mineral formation, hechtsbergite is only known in a few samples from less than 10 sites (as of 2018). In Germany, the mineral was only found in the Clara mine near Oberwolfach , a neighboring municipality of Hausach in Baden-Württemberg, as well as in the Oberbaumühle quarry near Windischeschenbach in the Upper Palatinate district of Neustadt an der Waldnaab (Bavaria).
Across Europe, hechtsbergite was still found in the uranium-bismuth-silver deposits of the former settlement of Smrkovec (German: Schönficht ) in the Czech Republic.
Worldwide, the mineral is only known from the copper deposit of the Wombat Hole prospecting or Wombat Hole Mine in the gorge of Morass Creek near Benambra in the Australian administrative region of East Gippsland Shire (Victoria), the Lavra da Posse (also Posse Mine ) near São Paulo José de Brejaúba in the Brazilian state of Minas Gerais and in mineral samples from a lithium-rich pegmatite near Nagatare in the prefecture of Fukuoka on the Japanese island of Kyushu.
See also
literature
- Werner Krause, Heinz J. Bernhardt, G. Blass, H. Effenberger, H.-W. Graf: Hechtsbergite, Bi 2 O (OH) (VO 4 ), a new mineral from the Black Forest, Germany . In: Neues Jahrbuch drove mineralogy, monthly books . tape 6 , May 1997, pp. 271–287 , doi : 10.1127 / njmm / 1997/1997/271 ( brief description from researchgate.net [accessed December 21, 2019]).
- John Leslie Jambor , Andrew C. Roberts: New Mineral Names . In: American Mineralogist . tape 83 , 1998, pp. 400–403 ( rruff.info [PDF; 538 kB ; accessed on December 21, 2019]).
- Seiichiro Uehara, Yohei Shirose: Namibite and hechtsbergite from the Nagatare mine, Fukuoka Prefecture, Japan . In: Journal of Mineralogical and Petrological Sciences . tape 108 , 2013, p. 105–110 ( jstage.jst.go.jp [PDF; 1.8 MB ; accessed on December 21, 2019]).
Web links
- Mineral Atlas: Hechtsbergite (Wiki)
- American-Mineralogist-Crystal-Structure-Database - Hechtsbergite. In: rruff.geo.arizona.edu. Retrieved December 21, 2019 .
Individual evidence
- ↑ a b Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: November 2019. (PDF 1720 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, November 2019, accessed December 21, 2019 .
- ^ A b 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. 469 (English).
- ^ David Barthelmy: Hechtsbergite Mineral Data. In: webmineral.com. Retrieved December 21, 2019 .
- ↑ a b c Werner Krause, Heinz J. Bernhardt, G. Blass, H. Effenberger, H.-W. Graf: Hechtsbergite, Bi 2 O (OH) (VO 4 ), a new mineral from the Black Forest, Germany . In: Neues Jahrbuch drove mineralogy, monthly books . tape 6 , May 1997, pp. 271–287 , doi : 10.1127 / njmm / 1997/1997/271 ( brief description from researchgate.net [accessed December 21, 2019]).
- ↑ a b c d e f Hechtsbergite . 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; 66 kB ; accessed on December 21, 2019]).
- ↑ a b Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
- ↑ a b c d Hechtsbergite. In: mindat.org. Hudson Institute of Mineralogy, accessed December 21, 2019 .
- ^ A b c John Leslie Jambor , Andrew C. Roberts: New Mineral Names . In: American Mineralogist . tape 83 , 1998, pp. 400–403 ( rruff.info [PDF; 538 kB ; accessed on December 21, 2019]).
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed December 21, 2019 .
- ↑ Seiichiro Uehara, Yohei Shirose: Namibite and hechtsbergite from the Nagatare mine, Fukuoka Prefecture, Japan . In: Journal of Mineralogical and Petrological Sciences . tape 108 , 2013, p. 105–110 ( jstage.jst.go.jp [PDF; 1.8 MB ; accessed on December 21, 2019]).
- ↑ Find location list for hechtsbergite at the Mineralienatlas and at Mindat , accessed on December 21, 2019.