Bournonite

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Bournonite
Bournonite-Quartz-bournonitequartzyaogangxianchina.jpg
High-gloss, partly bluish bournonite crystals on colorless to white quartz from the "Yaogangxian Mine", Yizhang , China (size: 9 cm × 6.5 cm × 6 cm)
General and classification
other names

Wheel ore

chemical formula PbCu [SbS 3 ]
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.GA.50 ( 8th edition : II / D.04a)
04/03/03/02
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol orthorhombic-pyramidal; mm 2
Space group Pn 2 1 m (No. 31, position 5)Template: room group / 31.5
Lattice parameters a  = 8.15  Å ; b  = 8.69 Å; c  = 7.79 Å
Formula units Z  = 4
Twinning predominantly quadruplets in the form of a cogwheel
Physical Properties
Mohs hardness 2.5 to 3 ( VHN 100 = 176 to 205)
Density (g / cm 3 ) measured: 5.83; calculated: 5.84
Cleavage imperfect after {010}, indistinct after {100} and {001}
Break ; Tenacity slightly scalloped to uneven; brittle
colour steel gray to iron black, tapering to a bluish tinge
Line color steel gray to black
transparency opaque
shine Metallic gloss to matt

Bournonite ( Rädelerz , Spießglanzbleierz , Schwarzspießglanzerz , Wölchit ) is a common mineral from the mineral class of the sulphides and sulfosalts . It crystallizes in the orthorhombic crystal system with the chemical composition PbCu [SbS 3 ] and develops short, prismatic or tabular crystals , but also granular or massive aggregates of steel gray to black color with the same line color . Fresh samples show a strong metallic luster on the surfaces of the opaque crystals, but older samples occasionally become bluish and dull.

Etymology and history

The first by Philip Rashleigh 1797 Endellionit named mineral was as determined by Bournon 1804 by Robert Jameson renamed Bournonite. Jacques Louis de Bournon (1751-1825) was a French crystallographer and mineralogist. The mining name wheel ore arose from the frequent discovery of quadruple adhesions of bournonite crystals, which look like a gear .

Bournonite was first discovered in the "Wheal Boys Mine" (also Trewetha Mine ) near St. Endellion in the English county of Cornwall .

classification

Already in the outdated 8th edition of the mineral classification according to Strunz , the bournonite belonged to the mineral class of the "sulfides and sulfosalts" and there to the department of the "complex sulfides (sulfosalts)", where together with seligmannite he created the "seligmannite series" with the system No. II / D.04a within the "lead copper spike luster group".

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 , the mineral was given the system and mineral number. II / E.16-20 . In the “Lapis system” this corresponds to the section “Sulfosalts (S: As, Sb, Bi = x)”, where bournonite also forms an independent but unnamed group together with seligmannite (as of 2018).

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and was updated by the International Mineralogical Association (IMA) until 2009, classifies bournonite in the category of "sulfarsenides, sulfantimonides, sulfbismutides". This is further subdivided according to the crystal structure and the possible presence of additional sulfur, so that the mineral according to its composition can be found in the subsection "Island sulfarsenides (Neso sulfarsenides) etc., without additional sulfur (S)", where together with Seligmannit and Součekit it forms the unnamed group 2.GA.50 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the bournonite to the class of "sulfides and sulfosalts" and there in the department of "sulfosalts". Here he is also in the " Seligmannite group " with the system no. 03.04.03 within the sub-section “ Sulphosalts with the ratio 3> z / y and the composition (A + ) i (A 2+ ) j [B y C z ], A = metals, B = semi-metals, C = non-metals" Find.

Chemism

The idealized (theoretical) composition of bournonite (PbCu [SbS 3 ]) consists of 42.40% lead , 13.00% copper , 24.91% antimony and 19.68% sulfur .

Due to mixed crystal formation with seligmannite (CuPbAsS 3 ), a small proportion of the antimony is usually replaced ( substituted ) by arsenic in natural bournonite . Bournonite samples can also contain smaller amounts of iron and / or zinc as a foreign addition . Measured silver proportions are, however, always due to adhesions with silver carriers.

Crystal structure

Bournonite crystallizes orthorhombically in the space group Pn 2 1 m (space group no. 31, position 5) with the lattice parameters a = 8.15  Å , b = 8.69 Å and c = 7.79 Å as well as 4 formula units per unit cell . Template: room group / 31.5

properties

In nitric acid to dissolve Bournonite with separation of sulfur and antimony on. In front of the soldering tube , it can easily be melted into a black ball, producing antimony smoke.

Education and Locations

Ring ore twin from the "Herodsfoot Mine" near Lanreath , Cornwall, England (size: 5 × 4.5 × 4.5 cm)

Bournonite forms hydrothermally in medium grade zinc , lead, and copper ore deposits . Accompanying minerals are galena , tetrahedrite , pyrite , siderite and others.

So far (as of 2011) Bournonite has been found at around 850 sites around the world. In addition to its type locality "Wheal Boys Mine", the mineral appeared in the United Kingdom (Great Britain) in several places in the English counties of Cornwall and Cumbria as well as in Wales and Scotland .

Well-known sites due to unusual bournonite finds include Machacamarca in the Bolivian Department of Potosí and Saint-Laurent-le-Minier in the French department of Gard , where crystals up to 10 cm in size were found. In the “Herodsfoot Mine” near Lanreath in Cornwall, complex twin- wheel ore over 5 cm in size were mined and crystals up to 4 cm in size were found near Příbram in the Czech Republic and in the Huancavelica region in Peru.

In Germany, bournonite was found in several places in the Black Forest in Baden-Württemberg, in Franconia and the Upper Palatinate in Bavaria, near Laubuseschbach in Central Hesse, near Clausthal and Sankt Andreasberg in Lower Saxony's Harz Mountains , at several sites in the Eifel , in Siegerland and in the Westerwald of North Rhine -Westfalen to Rhineland-Palatinate, in the Sauerland and Bergisches Land in North Rhine-Westphalia, in the Saarland community Nonnweiler , near Neudorf and Wolfsberg in Saxony-Anhalt, near Freiberg and Schneeberg in the Saxon Ore Mountains and near Gera , Greiz and Saalfeld in Thuringia.

In Austria, the mineral can be found in several regions of Carinthia , Salzburg and Styria as well as on the Eichberg near Gloggnitz in Lower Austria and in the Inn and Sill valley in Tyrol, and in Switzerland it can be found in the Ticino region of Malcantone as well as in the Binntal and the municipality Collonges VS in the canton of Valais.

Other locations are Argentina , Ethiopia , Australia , Bolivia , Brazil , Bulgaria , Chile , China , Fiji , Finland , Ghana , Greece , Greenland , Indonesia , Ireland , Italy , Japan , the Channel Island Jersey , Canada , Kazakhstan , Kyrgyzstan , Colombia , Korea , Kosovo , Croatia , Mexico , Mongolia , Namibia , New Zealand , Peru , Poland , Portugal , Romania , Russia , Sweden , Slovakia , Slovenia , Spain , South Africa , Tajikistan , Tunisia , Ukraine , Hungary , Uzbekistan , the United States of America (USA ) and Vietnam .

use

Bournonite is an important lead and copper ore and is used as a raw material for the extraction of these elements.

See also

literature

  • JL Bournon : Description of a triple sulfuret, of lead, antimony and copper, from Cornwall; with some observations upon the various modes of attraction which influence the formation of mineral substances, and upon the different kinds of sulfur of copper . In: Philosophical Transactions of the Royal Society of London . tape 94 , 1804, pp. 30–62 ( rruff.info [PDF; 4.4 MB ; accessed on December 27, 2019]).
  • Robert Jameson : Bournonite . In: System of Mineralogy . tape 2 , 1805, pp. 579–582 (English, rruff.info [PDF; 170 kB ; accessed on December 27, 2019]).
  • Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 475–476 (first edition: 1891).
  • Petr Korbel, Milan Novák: Mineral Encyclopedia (=  Villager Nature ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 56 .

Web links

Commons : Bournonite  - collection of images, videos and audio files

Individual evidence

  1. ↑ 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.  145 (English).
  2. ↑ a b c d Bournonite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 63  kB ; accessed on December 27, 2019]).
  3. ^ Charles Hatchett: Analysis of a Triple Sulfuret, of Lead, Antimony, and Copper, from Cornwall . In: Philosophical Transactions of the Royal Society of London . tape 94 , 1804, pp. 63–69 , doi : 10.1098 / rstl.1804.0007 , JSTOR : 107139 (English, royalsocietypublishing.org [PDF; 1,2 MB ; accessed on December 27, 2019]).
  4. ↑ 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 .
  5. ↑ 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 27, 2019 .
  6. ^ David Barthelmy: Bournonite Mineral Data. In: webmineral.com. Retrieved December 27, 2019 .
  7. ^ Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp.  295-296 .
  8. ↑ Find location list for bournonite in the Mineralienatlas and Mindat , accessed on December 27, 2019.