Salmiac

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Salmiac
Salammoniac-456369.jpg
Salmiak from the Eisden Mine, Maasmechelen , Limburg Province, Belgium (field of view: 1.5 cm)
General and classification
other names
chemical formula NH 4 Cl
Mineral class
(and possibly department) 		Halides
System no. to Strunz
and to Dana 		3.AA.25 ( 8th edition : III / A.03)
01/09/03/01
Crystallographic Data
Crystal system cubic
Crystal class ; symbol cubic hexakisoctahedral; 4 / m  3  2 / m
Space group Pm 3 m (No. 221)Template: room group / 221
Lattice parameters a  = 3.87  Å
Formula units Z  = 1
Frequent crystal faces {111}, {211}, {311}; also {112}, {113}, {011} and rarely {001}
Twinning after {111}
Physical Properties
Mohs hardness 1 to 2
Density (g / cm 3 ) measured: 1.532; calculated: 1.535
Cleavage indistinct to imperfect after {111}
Break ; Tenacity shell-like
colour colorless, white, light gray, light yellow to light brown
Line color White
transparency transparent to translucent
shine Glass gloss
Other properties
Chemical behavior easily soluble in water
Special features pungent salty taste

Salmiak is a rarely occurring mineral from the mineral class of " halides " with the chemical formula NH 4 Cl. It consists of ammonium and chloride in a ratio of 1: 1 and is therefore chemically ammonium chloride . Ammonia water , on the other hand, is referred to as ammonia .

Salmiak crystallizes in the cubic crystal system and only rarely develops small, edge-rounded crystals in the form of deltoidalikositetrahedra and twins with the octahedral surface (111) as the twin axis . Distorted crystals also appear tetragonal. The mineral is mostly found as stalactitic, fibrous or earthy mineral aggregates and as crusty coatings. In its pure form, ammonia is colorless and transparent. However, due to multiple light refraction due to lattice construction defects or polycrystalline training, it can also be translucent white and take on a yellowish to brownish color due to foreign admixtures.

Etymology and history

The Greek name hals ammoniakos , handed down by ancient authors , did not denote salmiak, but described a rock salt from Egypt (from the vicinity of a Jupiter-Ammon temple). The origin of the word for salmiak , which was erroneously reproduced as "sal ammoniacum" in the Middle Ages, is probably in the Latin expression sal armoniacum (more correctly sal armeniacum ) or Greek hals' armeniakón and had the meaning of "Armenian salt" and points to being impure in Armenia , especially ammonium chloride mixed with other ammonium salts and baking soda, naturally occurring salmia.

The compound chlorammonium was first described in 1546 by Georgius Agricola and called Salammoniac . However, he was referring to synthetically produced NH 4 Cl, which in the Orient was made from animal manure or obtained from rotten urine and table salt. The synthetic production of ammonia has been known to have been known since at least around 1100.

The word salmiak , derived from sal armoniacum , did not come into use until around 1700. Previously, the forms salmiax or salarmiax were mostly used in German-language texts .

A first mention of naturally grown salmiac can be found in the treatise "Experiments and Thoughts on a Natural and Grown Salmiak" written by the Saint Petersburg pharmacist Johann Georg Models in 1758 . The volcanoes Etna and Vesuvius in Italy, where the mineral precipitates at the points where volcanic gases escape, are considered to be the first places where natural salmiac was found . The natural formation of salmiak was confirmed in 1809 by Leopold von Buch . He observed the cooling of a lava flow on Vesuvius, which within a few hours covered itself with a thick, white crust of salmiac.

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , salmiac belonged to the mineral class of "halides" and there to the department of "simple halides", where it was the only member of the unnamed group III / A.03 .

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. III / A.04-010 . In the “Lapis system”, this also corresponds to the “Simple Halides” section, where Salmiak and Lafossait form an independent but unnamed group (as of 2018).

The 9th edition of Strunz's mineral systematics , which has been valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, classifies salmiak under the category of “simple halides without H 2 O”. However, this is further subdivided according to the molar ratio of cations (M) and anions (X), so that the mineral can be found according to its composition in the sub-section "M: X = 1: 1 and 2: 3", where it is named the "salmiak group" with the system no. 3.AA.25 and the other member Lafossait.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns salmiak to the class and division of the same name of "halides". Here he can also be found together with Lafossait in the unnamed group 09.01.03 within the sub-section "Anhydrous and hydrous halides with the formula AX".

Crystal structure

Salmiak crystallizes cubically in the space group Pm 3 m (space group no. 221) with the lattice parameter a  = 3.87  Å and one formula unit per unit cell . Template: room group / 221

The crystal structure consists of two cubic primitive partial lattices . One is from the Cl - - ions and the other of the (NH 4 ) + formed groups. Both partial lattices are pushed into one another in such a way that one Cl - ion is surrounded by eight (NH 4 ) + groups and vice versa. The crystalline structure of salmiak thus corresponds to the cesium chloride structure.

Below −30 ° C, the crystal lattice changes from the hexakisoctahedral to the less symmetrical hexakistrahedral structure with the space group P 4 3 m (No. 215) . Template: room group / 215

properties

Salmiak is easily soluble in water and has a pungent salty taste. When heated , ammonia evaporates quickly and completely.

Education and Locations

Sulfur and salmiac, efflorescence from the dump at the Oberhausen colliery due to the dump fire - exhibited in the Ruhr Museum at the Zollverein colliery
Feather-like mineral aggregate from Ravat near the Jaghnob , Tajikistan (size: 3.3 cm × 1.4 cm × 1.4 cm)

Salmiac is mainly formed through volcanic activity , where it is deposited from volcanic gases either directly on the volcanic crater or on fumaroles and solfataras . Another possibility of resublimation from the gas phase is in burning coal seams and spoil heaps . In addition, the mineral can also arise as an accessory component in guano (excrement from birds). The accompanying minerals include sulfur , realgar and auripigment , mascagnin (natural ammonium sulfate ) and Tschermigit .

As a rare mineral formation, salmiac could only be detected at a few sites, whereby so far (as of 2019) almost 110 sites are known. In Italy, the mineral is known from other volcanic deposits such as the Phlegraean Fields and Stromboli .

The burning coal heaps near Kladno in the Czech region of Central Bohemia, where crystals of over one centimeter have been found, are known for their extraordinary crystal finds.

In Germany Salmiak occurred in different coal mines like the mine Anna and Zeche Alstaden in North Rhine-Westphalia and as well as at Oelsnitz / Erzgeb. and the Königin-Carola-Schacht near Freital in Saxony and burning seams and heaps such as the Burning Mountain near Saarbrücken in Saarland and the sedimentation heaps from the Lichtenberg opencast mine near Lichtenberg in Thuringia.

In Austria, the mineral was found, among other places, on the Muttlkogel in the Zangtal coal mining area, as well as in the Munzenberg area and in the Seegraben mining area in Styria. It was also discovered in a salt mine near Hall in Tirol .

The only known site in Switzerland so far is the Bex salt mine in the canton of Vaud.

Other locations are in Belgium, Chile, China, France, Iceland, Japan, Mexico, the Netherlands, Norway, Peru, Poland, Portugal, Russia, Spain, South Africa, Tajikistan, the Czech Republic, Ukraine, Hungary, Venezuela, in the United States United Kingdom (UK) and the United States of America (USA).

use

Salmiak is known, among other things, for its use in salmiak liquorice or salmiak pastilles . In addition, the mineral or, better, its synthetic counterpart, is also used for the production of cold mixtures and in dyeing and tannery (see also the use of ammonium chloride ).

See also

literature

  • Johann Georg Models: Experiments and thoughts about a natural or grown salmiac, together with a discussion of some of the objections made by Mr. Baron about Persian salt . Joh. Friedrich Gleditschens Handlung, Leipzig 1758 ( limited preview in the Google book search).
  • Julius Ruska : Sal ammoniacus, nusâdir and Salmiak . In: Meeting reports of the Heidelberg Academy of Sciences: philological-historical class . tape 14 , no. 5 , 1923, pp. 3-23 .
  • Georgius Agricola : De Re Metallica . Dover Publications, New York 1950, pp. 560 , Sal-ammoniac (English, rruff.info [PDF; 216 kB ; accessed December 20, 2019] Latin: De Re Metallica . 1556. Translated by Herbert Clark, Lou Henry Hoover).
  • BK Vainshtein: Refinement of the structure of the group NH 4 in the structure of ammonium chloride . In: Trudy Instituta Kristallografii Akademiya Nauk SSSR . tape 12 , 1956, pp. 18-24 (English).
  • Helga Dittberner: On the history of salmiac in Islamic and pre-Islamic chemistry . In: Rete . tape 1 , 1972, p. 347-362 .

Web links

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

Individual evidence

  1. ↑ a b c d e f Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . De Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp.  318-319 .
  2. ↑ 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 20, 2019 .
  3. ↑ a b c d 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.  150 (English).
  4. ↑ a b c d Sal ammoniac . 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; 67  kB ; accessed on December 20, 2019]).
  5. ↑ a b c Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp.  487 (first edition: 1891).
  6. ^ Emil Ploß: The origin of the word form "Salmiak" . In: Archives for the Study of Modern Languages ​​and Literatures . tape 195 , no. 4 , 1959, pp. 321-324 .
  7. ↑ Dieter Lehmann: Two medical prescription books of the 15th century from the Upper Rhine. Part I: Text and glossary (=  Würzburg medical-historical research . No. 34 ). Horst Wellm, Pattensen / Han. 1985, ISBN 3-921456-63-0 , pp. 245 .
  8. ↑ Gundolf Keil: The "Cirurgia" Peters von Ulm. Investigations into a memorial of old German specialist prose with a critical edition of the text (= research on the history of the city of Ulm. 2). Stadtarchiv, Ulm 1961 (also philosophical dissertation Heidelberg 1960), p. 454.
  9. ↑ Wolfgang Schneider : Investigations into the medicinal treasure of the past, 3rd part: The most important pharmaceutical-chemical products of the alchemical and pre-chemical times . In: drug research . tape  10 , 1960, p. 509-513 , here: p. 510 f. .
  10. ↑ a b c 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. 306-307 .
  11. ^ Franz Maria Feldhaus : The technology of prehistoric times, the historical time and the primitive peoples . 2nd Edition. Moos, Munich 1965, p.  894 ( available online at archive.org  - Internet Archive ).
  12. ↑ 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 .
  13. ↑ 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 20, 2019 .
  14. ↑ Localities for Salammoniac. In: mindat.org. Hudson Institute of Mineralogy, accessed December 20, 2019 .
  15. ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (=  Dörfler Natur ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 72 .
  16. ↑ Find location list for Salmiak ( Salammoniac ) in the Mineralienatlas and Mindat , accessed on December 20, 2019.