Valentinite
| Valentinite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | Sb 2 O 3 |
|
Mineral class (and possibly department) |
Oxides and hydroxides |
|
System no. to Strunz and to Dana |
4.CB.55 ( 8th edition : IV / C.01) 03/04/11/01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m |
| Space group | Pccn (No. 56) |
| Lattice parameters | a = 4.91 Å ; b = 12.46 Å; c = 5.41 Å |
| Formula units | Z = 4 |
| Frequent crystal faces | {011}, {054}, {100}, {010} |
| Physical Properties | |
| Mohs hardness | 2.5 to 3 |
| Density (g / cm 3 ) | measured: 5.76; calculated: 5.828 |
| Cleavage | perfect after {110}, imperfect after {010} |
| Break ; Tenacity | uneven; brittle |
| colour | colorless, white, gray, yellowish, brownish |
| Line color | White |
| transparency | transparent to translucent |
| shine | Diamond luster, pearlescent luster on cleavage surfaces |
| Crystal optics | |
| Refractive indices |
n α = 2.180 n β = 2.350 n γ = 2.350 |
| Birefringence | δ = 0.170 |
| Optical character | biaxial negative |
Valentinite , also known as antimony blossom out of date , is a rather seldom occurring mineral from the mineral class of "oxides and hydroxides". It crystallizes in the orthorhombic crystal system with the chemical composition Sb 2 O 3 and is therefore chemically antimony (III) oxide .
Valentinite usually develops tabular to prismatic crystals , but also occurs in the form of radiating, tufted, fan-shaped or star-shaped as well as granular to massive mineral aggregates . Unharmed crystal surfaces have a diamond-like sheen , whereas cleavage surfaces have a more mother-of-pearl shimmer. In its pure form, Valentinite is colorless and transparent. However, due to multiple light refraction due to lattice construction defects or polycrystalline formation, it can also appear white and, due to foreign admixtures, take on a gray or yellowish to brownish color, the transparency decreasing accordingly.
With a Mohs hardness of 2.5 to 3, valentinite is one of the soft to medium-hard minerals that can be scratched with a copper coin more easily than the reference mineral calcite (3).
Etymology and history
The name Valentinite for the rhombic antimony oxide, which is still valid today, was coined by Wilhelm von Haidinger in 1845 , who named the mineral after the medieval author of alchemical writings Basilius Valentinus . The person behind Valentinus has not yet been identified, but is said to have written a well-known work on the representation of the element antimony from stibnite ( antimonite ) and "flores antimonii" ("Triumphwagen Antimonii", published in 1604 by Johann Thölde ).
However, the mineral was already known before Haidinger under various synonyms such as white spit gloss ore (after Klaproth , 1789) or white spit glass ore (after Werner , 1789) and spit gloss white , which are no longer in use. In contrast , the term antimony blossom , coined by Karl Caesar von Leonhard in 1821, is still listed in modern specialist literature as a synonym for valentinite, and occasionally the rather uncommon term white skewer gloss .
As type locality (first location) the "mine of Chalanches" in true Allemond (English Allemont ) in the French department of Isère (Rhône-Alpes).
classification
Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the valentinite belonged to the mineral class of "oxides and hydroxides" and there to the department of "oxides with the molar ratio metal: oxygen = 2: 3 (M 2 O 3 and related compounds) ", where together with claudetite he created the" claudetite-valentine group "with the system no. IV / C.01 and the other member Auroantimonat .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), classifies the valentinite in the expanded section of "Oxides with the molar ratio of metal: oxygen = 2: 3, 3: 5 and comparable" . This is further subdivided according to the relative size of the cations involved , so that the mineral can be found according to its composition in the sub-section "With medium-sized cations", where it is the only member of the unnamed group 4.CB.55 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns valentinite to the class of "oxides and hydroxides" and there in the department of "oxide minerals". Here he is to be found as the only member of the unnamed group 04.03.11 within the subsection "Simple oxides with a cation charge of 3+ (A 2 O 3 )".
Crystal structure
-oxide-valentinite-xtal-2004-3D-balls.png)
Valentinite crystallizes orthorhombically in the space group Pccn (space group no. 56) with the lattice parameters a = 4.91 Å ; b = 12.46 Å and c = 5.41 Å as well as four formula units per unit cell .
The crystal structure of valentinite consists of SbO 3 molecules that are linked to one another via shared O atoms and form chains parallel to the c-axis. The chains are only connected by weak Van der Waals and Coulomb forces and the distances between them are relatively large, which is also the reason for the low hardness and perfect cleavability of the mineral.
Modifications and varieties
The compound Sb 2 O 3 is dimorphic and, in addition to orthorhombic crystallizing valentinite, also occurs as cubic crystallizing senarmontite .
Education and Locations
Valentinit as the rarer forms similar Senarmontit as a secondary mineral by weathering of antimony or antimony various minerals such as stibnite in the oxidation zone of ore - deposits . Other accompanying minerals include cervantite , kermesite , stibiconite and tetrahedrite .
As a rather rare mineral formation, valentinite can sometimes be abundant at various locations, but overall it is not very common. In total, more than 300 sites are known to date (as of 2014). In addition to its type locality "Mine des Chalanches" near Allemond and the "Mine Gueydon" near Regny in the Loire department in Rhône-Alpes, the mineral appeared in France, among others, in the Auvergner departments Cantal and Haute-Loire , in the department Finistère (Brittany) and at some locations in different regions.
Příbram in the Czech region of Central Bohemia, where well-formed crystals up to three centimeters long have been found, is known for its extraordinary Valentinite finds. Similar good finds of up to two centimeters in size were also found in the area around Oruro in Bolivia. Radial aggregates with a diameter of up to four centimeters are mainly known from Pezinok and Pernek in Slovakia and the largest known pseudomorphoses from Valentinite to Stibnite of up to 35 centimeters in length were found in the Xikuangshan antimony deposit near Lengshuijiang in the Chinese province of Hunan .
In Germany, the mineral has so far been found in several places in the Black Forest such as St. Ulrich and Sulzburg in Baden-Württemberg, in the Sauerland and Siegerland in North Rhine-Westphalia and in the Westerwald in Rhineland-Palatinate. There is also the “Silver Rose” mine near Brandholz - Goldkronach in Bavaria, the “Catharina Neufang” mine near Sankt Andreasberg in Lower Saxony, the “Hope” mine (Spes mine) at Martinsknipp near Ahrbrück , “ Friedrichssegen ” in Lahntal and “Carolina” "On the Moschellandsberg in Rhineland-Palatinate, the" Graf Jost-Christian-Zeche "near Wolfsberg (Sangerhausen) in Saxony-Anhalt, the pits" New Hope of God "near Bräunsdorf (Oberschöna) and" St. Peter ”at Kottenheide- Schöneck / Vogtl. in Saxony and the “Kuhberg” quarry near Neumühle / Elster (Greiz district) in Thuringia are known as sites for valentinite.
In Austria, valentinite has so far been found mainly in Carinthia , where it appeared in the area around Friesach and Hüttenberg as well as in the mountain range of the Kreuzeck group . In addition, the mineral was found in an antimony mine near Stadtschlaining in Burgenland, near Maltern in the Lower Austrian municipality of Hochneukirchen-Gschaidt , on the Wetterbauersattel near Mixnitz and on a slag dump near Walchen (municipality of Öblarn ) in Styria and at some sites in the area around Brixlegg and Schwaz in Tyrol.
In Switzerland, you know the mineral so far only from the Puschlav -Tal in the canton of Grisons and Ticino region Malcantone .
Other locations include Algeria, Australia, Brazil, Chile, Finland, France, Greece, Greenland, Isle of Man, Italy, Japan, Canada, Kyrgyzstan, Luxembourg, Macedonia, Mexico, New Caledonia, New Zealand, Norway, Portugal, Romania, Russia, Sweden, Serbia, Slovakia, Slovenia, Spain, South Africa, Thailand, Turkey, Hungary, the United Kingdom (England, Scotland) and the United States of America (California, Idaho, Nevada, Oregon, Utah, Washington).
use
Valentinite is only used as antimony ore when it is locally accumulated together with stibnite .
See also
literature
- W. Haidinger : Second class: Geogenide. II. Order. Barytes VIII. Antimony Barytes. Valentinite . In: Handbook of determining mineralogy . Braumüller and Seidel, Vienna 1845, p. 499–506 ( rruff.info [PDF; 512 kB ; accessed on August 28, 2017]).
- Helmut Schrätze , Karl-Ludwig Weiner : Mineralogy. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 386-388 .
Web links
- Mineral Atlas: Valentinite (Wiki)
- Database-of-Raman-spectroscopy - Valentinite (English)
- American-Mineralogist-Crystal-Structure-Database - Valentinite (English)
Individual evidence
- ↑ a b c d e Hans Lüschen: The names of the stones. The mineral kingdom in the mirror of language . 2nd Edition. Ott Verlag, Thun 1979, ISBN 3-7225-6265-1 , p. 173 .
- ↑ 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. 197 .
- ↑ Webmineral - Valentinite
- ^ A b Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 386 .
- ↑ a b Valentinite . 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; 68 kB ; accessed on August 28, 2017]).
- ↑ a b c d Mindat - Valentinite
- ↑ Mindat - White Skewer Luster Ore
- ↑ Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 415 .
- ↑ Mindat - Number of localities for Valentinite
- ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (= Dörfler Natur ). Nebel Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 81 .
- ↑ Find location list for Valentinite at the Mineralienatlas and at Mindat