Auripigment
| Auripigment | |
|---|---|
 |
|
| General and classification | |
| chemical formula | As 2 S 3 |
|
Mineral class (and possibly department) |
non-metallic sulphides |
|
System no. to Strunz and to Dana |
2.FA.30 ( 8th edition : II / F.02) 11/02/01/01 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 1 / n (No. 14, position 2) |
| Lattice parameters |
a = 11.475 Å ; b = 9.577 Å; c = 4.256 Å β = 90.68 ° |
| Formula units | Z = 4 |
| Frequent crystal faces | {100}, {010}, {301}, {110}, {011}, {210} |
| Physical Properties | |
| Mohs hardness | 1.5 to 2 |
| Density (g / cm 3 ) | measured: 3.49; calculated: 3.48 |
| Cleavage | perfect after {010}, imperfect after {100} |
| Break ; Tenacity | leafy, pliable |
| colour | lemon yellow to bronze yellow |
| Line color | light yellow |
| transparency | transparent to translucent |
| shine | resinous greasy sheen, mother-of-pearl sheen |
| Crystal optics | |
| Refractive indices |
n α = 2.400 n β = 2.810 n γ = 3.020 |
| Birefringence | δ = 0.620 |
| Optical character | biaxial negative |
| Pleochroism | yellow-yellow-green-yellow |
| Other properties | |
| Chemical behavior | Soluble in potassium hydroxide (KOH), turns red when heated |
| Special features | highly toxic! |
Orpiment , vernacular as arsenic panel , noise yellow or orpiment and under the common in the English language name Orpiment known is a common mineral from the mineral class of "sulfides and sulfosalts" with the chemical formula As 2 S 3 . From a chemical point of view, it is therefore arsenic (III) sulphide with a molar ratio of arsenic : sulfur equal to 2: 3.
Auripigment crystallizes in the monoclinic crystal system and rarely develops small, prismatic crystals or pseudo- rhombic twins . It is mostly found in the form of leafy, columnar or fibrous mineral aggregates and crusty coatings. The surfaces of the transparent to translucent crystals have a resin-like to grease-like sheen , whereas cleavage surfaces have a more mother-of-pearl shimmer . In general, aura pigment is from lemon to golden yellow in color. Depending on the weathering condition or the type of foreign admixture, the color can also appear bronze-yellow to brownish-yellow or have a tinge of reddish or greenish. On the other hand, the mineral always leaves a bright yellow line on the marking board .
Although orpiment is one of the highly toxic minerals, it was like because of its brilliant golden yellow color and pigment - color in the painting used.
Etymology and history
The German name Auripigment (from Middle Latin auripigmentum ) is derived (like Middle High German ôrpermint , originated from ôrpiment , and Middle Dutch operment ) from the Latin word aurum (gold). It was also known under the Greek Arrhenicon and derived from it Arsenicon, Arsikon, Arzikon, Arsenicum, Arsenik . In German-speaking countries, terms such as Risigallum, Ruschgäl, Rüschelecht and Rauschgelb appear, later also Königsgelb, Arsenblende, yellow Hüttenrauch and Operment (um) . In France and England it was known and is known as orpiment, in Italy as oropimento.
classification
Already in the outdated 8th edition of the mineral classification according to Strunz , auripigment belonged to the mineral class of "sulfides and sulfosalts" and there to the department "complex sulfides (sulfosalts)", where it was included in the appendix to the sulfides of semimetals and together with dimorphin , gerstleyite , Getchellit , Metastibnit , Patrónit ( Patronit ), Realgar formed the "Patronit-Realgar-Gruppe".
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 / F.02-70 . In the "Lapis Classification" this represents the department "sulfides with non-metallic character" where orpiment with Alacránit , Anorpiment , Bonazziit , Duranusit , Dimorphin, Laphamit , Pararealgar , realgar and Uzonit an independent but unnamed group forms (as of 2018) .
The 9th edition of Strunz's mineral systematics , valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also assigns the auripigment to the class of “sulfides and sulfosalts”, but in the “sulfides of arsenic, alkalis” category ; Sulphides with halides, oxides, hydroxides, H 2 O “. This is also more precisely subdivided according to the type of elements contained in the formula, so that the mineral can be found according to its composition in the sub-section "with As, (Sb), S", where it is the unnamed group, only together with laphamite 2.FA.30 forms.
The systematics of minerals according to Dana also assigns the auripigment to the class of "sulfides and sulfosalts" and there into the department of "sulfide minerals". Here it is the eponymous mineral of the "auripigment group" with the system no. 02.11.01 and the other member Getchellit within the subsection " Sulphides - including selenides and tellurides - with the general composition A m B n X p , with (m + n): p = 2: 3 ".
Chemism
Pure aura pigment contains 60.9% arsenic and 39.1% sulfur, but can also contain additions of selenium (Se), antimony (Sb), vanadium (V) and germanium (Ge). In addition, the mineral is often contaminated with clay minerals , silicon dioxide (SiO 2 ) and / or stibnite ( antimonite , Sb 2 S 3 ).
Crystal structure
Auripigment crystallizes in the monoclinic crystal system in the space group P 2 1 / n (space group no. 14, position 2) with the lattice parameters a = 11.475 Å , b = 9.577 Å, c = 4.256 Å and β = 90.68 Å as well as four formula units per unit cell .
The crystal structure consists of As 2 S 3 layers parallel to the crystal face (010). Strong, homopolar (non-polar) covalent bonds prevail within the layers and weak van der Waals bonds prevail between the layers , which is the reason for the mineral's perfect cleavability .
properties
In the transmitted light microscope you can see coarse, transparent yellow particles that have a leafy structure. Numerous cleavage surfaces can be seen. The mineral is birefringent, extremely bright, abnormal red and blue-green interference colors appear under crossed polarizers .
When heated, auripigment turns red and in front of the soldering tube it shows the same reactions as realgar .
Education and Locations
Auripigment is formed from arsenic (As 2 O 3 ) or pararealgar (AsS) under UV light from realgar and therefore usually has the same sites as this. So far, around 480 sites for auripigment are known worldwide (status: 2014).
The Shimen arsenic gold deposit in the Chinese province of Hunan, the La Libertad mine near Quiruvilca in the Peruvian region of La Libertad and the Getchell, Lone Tree and Twin Creeks mine in Humboldt County (Nevada) are known for their extraordinary auripigment discoveries. in the USA, where well-formed crystals several centimeters long emerged.
In Germany, auripigment has so far been found mainly in the Black Forest in Baden-Württemberg and in the Ore Mountains in Saxony, in Austria the mineral is mainly known from various sites in Carinthia and in Switzerland so far only the "Lengenbach" mine in the Binntal (canton Wallis ) known as the auripigment site.
Other locations include Australia, Chile, France, Italy, Japan, Canada, Romania, Russia, Slovakia and Turkey.
Historical use
The reddish-yellow aura pigment has been used to imitate gold since ancient times, because it “resembles gold like no other color,” says Cennino Cennini . In source writings such as the Leiden Papyrus X , the Lucca Manuscript or the Mappae Clavicula there are many recipes for gold scripts. The auripigment has been proven in ancient Egyptian art , wall paintings in India and China , medieval book illuminations , sculpture frames and panel paintings , in Venetian paintings from the 15th and 16th centuries as well as Dutch still lifes from the 17th century and Tibetan thankas from the same period.
Before the invention of chrome yellow , auripigment was the brightest yellow known in painting. Today it is being replaced by non-toxic tar dyes . A beautiful and famous example of the use of aura pigment is Titian's painting "Bacchus and Ariadne". The bright orange in the cymbal player's coat is painted with realgar / auripigment.
Auripigment was already traded as a medicine and cosmetic product in ancient Greece, the Roman Empire and China. It was a component of Rhusma Turcorum (also: rusma turcorum), one of the oldest known means for removing body hair. Rhusma Turcorum was made from a mixture of aura pigment, slaked lime and starch mixed into a paste.
The "Handbook of Therapeutic Medicine" by Dr. Friedrich Oesterlen from 1844 shows a recipe for Rhusma Turcorum . Oestelen explains that it is not the arsenic sulphate, but the calcium sulphide resulting from its decomposition by lime that is the active ingredient. He goes on to explain that auripigment is also used as a caustic agent in cancer: "[...] z. B. in Belgium applied cut into small troehisks (Delnaie). The Chinese also smoke it with tobacco (Macgnowan). "
The use in Rhusma Turcorum also corresponds to the use of auripigment in the tannery to depilate fur.
In the Middle Ages, auripigment was also used as an additive to sealing wax and, because of its distinctive yellow color, was always of interest to alchemists looking for a method to produce gold.
Modern applications
Auripigment is still partly used in the production of oilcloth , linoleum , semiconductors and photoconductors and fireworks .
In Rhusma turcorum it is still used as a depilatory in rural India. It continues to be used in the leather industry to remove hair from hides.
Precautions
Auripigment contains a high proportion of arsenic and, like realgar , is therefore classified as a toxic substance ( H-phrases H301 toxic if inhaled , H331 toxic if swallowed , H410 very toxic to aquatic organisms with long-term effects ). Handling auripigment requires special precautions, such as keep locked up; Use protective gloves and eye protection; Do not eat, drink or smoke at work; Avoid release to the environment and dispose of as hazardous waste. When transporting relevant quantities, it falls under dangerous goods class 6.1 with the hazard number 60 above UN number 1557. A companion of auripigment is arsenic , which is significantly more toxic than pure arsenic due to its good solubility. The orally ingested, lethal dose for humans can be less than 0.1 g!
Many historical sources warn of the high toxicity of the aura pigment. In 1738 Sprong described it: “Royal yellow: This is made from the best pieces of aura pigment and is therefore very poisonous. The user should therefore not try to smell it by holding his nose over it ”. Also Valentin Boltz warns in his Illuminierbuch 1549 explicitly: "And you, you hüt pensel leckest not this color because it is Schedlich". Cennini describes it as "propio tosco", truly poisonous, and in many books (Schramm) and lists of pigment manufacturers (Kremer) it is classified in poison class 1 or 2. However, there is also the statement that arsenic trisulfide is not very toxic. Since it is insoluble in water and hydrochloric acid , it cannot be absorbed by the body, or only in small quantities. Symptoms of poisoning can be traced back to "contamination" with the breakdown product arsenic (As 2 O 3 ), which was used as the famous (suicide) poison.
In addition to its toxicity, a further disadvantage of the auripigment is particularly evident in old paintings: when exposed to light (direct sunlight), the solvents used in painting react with the auripigment, so that the yellow disintegrates over the centuries. This affects especially on greens from which the old masters in the absence of a beautiful green pigment frequently from Auripigmentfarblacken and a blue have mixed pigment: this is the reason that in many ancient landscape paintings by the fading of the yellow tone, for example, the trees blue have become .
See also
literature
- 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. 340 .
- Martin Okrusch, Siegfried Matthes: Mineralogy. An introduction to special mineralogy, petrology and geology . 7th, completely revised and updated edition. Springer, Berlin [a. a.] 2005, ISBN 3-540-23812-3 , pp. 42 .
- Dietlinde Goltz: Studies on the history of mineral names in pharmacy, chemistry and medicine from the beginnings to Paracelsus (= Sudhoffs archive . Volume 14 ). Wiesbaden 1972, p. 239–242 (mathematical and scientific dissertation, Marburg an der Lahn 1966).
Web links
- Mineral Atlas: Auripigment (Wiki)
- Orpiment search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed December 11, 2019 .
- Auripigment. In: kremer-pigmente.de. Kremer Pigments, accessed December 11, 2019 .
- Orpiment. In: colourlex.com. Retrieved December 11, 2019 .
Individual evidence
- ↑ a b c American-Mineralogist-Crystal-Structure-Database - Orpiment. In: rruff.geo.arizona.edu. Retrieved December 11, 2019 .
- ^ 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. 307-308 .
- ↑ a b c Orpiment . 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; 64 kB ; accessed on December 11, 2019]).
- ↑ a b c d Orpiment. In: mindat.org. Hudson Institute of Mineralogy, accessed December 11, 2019 .
- ↑ 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. 179 ( Operment : 1546. Interpretatio after Agricola ).
- ↑ 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 .
- ↑ 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 11, 2019 .
- ^ David Barthelmy: Orpiment Mineral Data. In: webmineral.com. Retrieved December 11, 2019 .
- ↑ 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. 340 .
- ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 482-483 (first edition: 1891).
- ↑ Localities for Orpiment. In: mindat.org. Hudson Institute of Mineralogy, accessed December 11, 2019 .
- ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (= Dörfler Natur ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 64 .
- ↑ Locations for Auripigment (Orpiment) in the Mineralienatlas and Mindat , accessed on December 11, 2019.
- ↑ Arthur Lucas, Joyce Plesters: Titian's "Bacchus and Ariadne" . In: National Gallery Technical Bulletin . tape 2 , 1978, p. 25–47 (English, nationalgallery.org.uk [PDF; 24.4 MB ; accessed on December 12, 2019]).
- ↑ Titian's "Bacchus and Ariadne", Pigment analysis ( Memento of March 4, 2016 in the Internet Archive )
- ↑ Hair Removal - The History of Hair Removal. In: retrochicks.de. Retrieved December 12, 2019 .
- ↑ Fr. Oesterlen : Handbook of remedies theory . 7th edition. Verlag der H. Laupp'schen Buchhandlung, Tübingen 1861, p. 99 ( available online at archive.org - Internet Archive ).
- ↑ Entry for CAS no. 1303-33-9 in the GESTIS substance database of the IFA , accessed on November 3, 2015 (JavaScript required)