Adamin
| Adamin | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula |
|
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Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.BB.30 ( 8th edition : VII / B.04) 06/41/06/03 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m |
| Space group | Pnnm (No. 58) |
| Lattice parameters | a = 8.30 Å ; b = 8.51 Å; c = 6.04 Å |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 3.5 |
| Density (g / cm 3 ) | measured: 4.32 to 4.48; calculated: 4.435 to 4.444 |
| Cleavage | good after {101}; indistinct after {010} |
| Break ; Tenacity | uneven to slightly scalloped; brittle |
| colour | yellow-green, yellow, green, pink, purple, colorless |
| Line color | White |
| transparency | transparent to translucent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.708 to 1.722 n β = 1.708 to 1.722 n γ = 1.763 to 1.773 |
| Birefringence | δ = 0.055 |
| Optical character | biaxial, alternating |
| Axis angle | 2V = 78 to 90 ° |
| Other properties | |
| Special features | lemon yellow fluorescence and phosphorescence |
Adamin is a rather seldom occurring mineral from the mineral class of " phosphates , arsenates and vanadates " with the chemical composition Zn 2 (AsO 4 ) (OH) or in the crystal chemical structural formula according to Strunz Zn 2 [OH | AsO 4 ]. Chemically, adamin is therefore a zinc arsenate with additional hydroxide ions .
Adamin crystallizes in the orthorhombic crystal system and mainly develops short to long prismatic and bipyramidal crystals . In addition, acicular and radial radial mineral aggregates are also known. In its pure form, which is rarely found, Adamin is colorless and transparent. Usually it takes on a yellow, yellow-green to green or pink to violet color due to foreign admixtures . The transparent to translucent crystals show a glass-like sheen on the surfaces .
Etymology and history
The mineral was discovered by the French mineralogist Gilbert Joseph Adam (1795–1881) in Chañarcillo in the Chilean Región de Atacama . It was described in 1866 by the French chemist and mineralogist Charles Friedel (1832–1899), who named it after its discoverer.
The type material of the mineral is in the mineralogical collection of Adam der Mines ParisTech ( Ecole Nationale Supérieure des Mines , ENSM) and the collection no. 4184 as well as in the Muséum national d'histoire naturelle in Paris under the collection no. 66.34 .
classification
Already in the outdated 8th edition of the mineral classification according to Strunz , the Adamin belonged to the department of "Anhydrous phosphates, arsenates and vanadates with foreign anions ", where he named the "Adamin series" with the system no. VII / B.04a and the other members Eveit , Libethenit and Olivenit .
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, albeit revised and updated, form of Karl Hugo Strunz's system , the mineral was given the system and mineral number. VII / B.06-30 . In the "lapis Classification" this also corresponds to the department "Anhydrous phosphates, with foreign anions F, Cl, O, OH" where Adamin together with Auriacusit , Eveit, Libethenit, Olivenit, Paradamin , Tarbuttit , Zincolibethenit and Zinkolivenit the "Libethenite -Group "(VII / B.06) forms (status 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, also assigns the adamin to the department 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 other anions to the phosphate, arsenate or vanadate complex, so that the mineral is classified in the sub-section “With only medium-sized cations; (OH etc.): RO 4 ≤ 1: 1 “can be found where, together with auriacusite, eveit, libethenite, olivenite, zincolibethenite and zinc olivenite, the“ libethenite group ”with the system no. 8.BB.30 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , also assigns the adamin to the class of "phosphates, arsenates and vanadates" and there to the category of "anhydrous phosphates, etc., with hydroxyl or halogen". Here he is in the " olivite group " with the system no. 41.06.06 within the subsection “Anhydrous phosphates etc., with hydroxyl or halogen with (A) 2 (XO 4 ) Z q ”.
Chemism
The idealized (theoretical) composition of Adamin (Zn 2 (AsO 4 ) (OH)) consists of 45.61% zinc (Zn), 26.13% arsenic (As), 27.90% oxygen (O) and 0, 35% hydrogen (H). When analyzing natural adamin samples from the type locality , a small proportion of iron oxide of 1.48% and traces of manganese oxide could also be determined. Samples from Mapimí in Mexico, on the other hand, showed only small amounts of silicon dioxide (SiO 2 ) of 0.26%.
Crystal structure
Adamin crystallizes orthorhombically in the space group Pnnm (space group no. 58) with the lattice parameters a = 8.30 Å , b = 8.51 Å and c = 6.04 Å as well as four formula units per unit cell .
properties
Adamin glows green to yellow-green under UV light .
Together with olivenit it forms a mixed series with copper content increasing after olivenit . Since cuproadamine occurs within the mixed series, it is not recognized as an independent variety on various occasions.
Varieties and modifications
The compound Zn 2 [OH | AsO 4 ] is dimorphic and occurs naturally in addition to the orthorhombic adamin as a triclinic crystallizing paradamine .
In the varieties aluminum- adamin, cupro adamin, cobalt adamin, manganese adamin and nickel adamin, the zinc contained in adamin is partially replaced by the elements mentioned in the variety names. Varieties containing copper stand out for their strong green color, while varieties containing manganese take on a purple hue.
Education and Locations
Adamin usually forms together with aurichalcite , hemimorphite , konichalcite and smithsonite in the oxidation zone of arsenic-rich solutions or in zinc deposits .
As a rather rare mineral formation, adamin can sometimes be abundant at different sites, but overall it is not very common. So far, around 400 locations have been documented for Adamin (as of 2020). In addition to its type locality Chañarcillo, the mineral has so far only been found in the nearby Veta Negra mine in the Pampa Larga district in the Atacama region.
In Germany, Adamin appeared in Baden-Württemberg in many places in the Black Forest such as Freudenstadt , Lahr / Black Forest , Wittichen and the Clara mine near Oberwolfach; in the Harz Mountains in Lower Saxony such. B. in the Glücksrad mine near Oberschulenberg and Sankt Andreasberg and in North Rhine-Westphalia on the Maubacher Bleiberg , in the Leibnitz mine and the Schöne Aussicht mine near Burbach (Siegerland) . In addition, some sites in Bavaria, Hesse, Rhineland-Palatinate, Saxony-Anhalt and things are known.
In Austria, the mineral could so far on the Feistritz Alp near Feistritz an der Gail , the Unterbuchach Alp near Kirchbach , on the Elferspitz in the area of the Plöckenpass and in the pit "Judengras" near Podlanig ( Lesachtal ) in the Gailtaler and Carnic Alps as well as in one Copper deposit in the Rijavitzagraben (also Jeravitzagraben or Remscheniggraben ) and in the Neufinkenstein - Grabanz district in Carinthia; in the St. Anna and St. Joachim mines near Annaberg in Lower Austria; in the Windbachtal in the Hohe Tauern , in the area of Korein and Frommerkogel near Radstadt and in a prehistoric spoil dump in the Schwarzleograben near Hütten (municipality of Leogang ) in the Salzburger Land as well as in many places in the Brixlegg - Rattenberg district such as the Silberberg and the Gratlspitz , the Hofer Tratte mine near Hof , on the Groß- and Kleinkogel near St. Gertraudi and in the Ringenwechsel area near Schwaz in Tyrol.
In Switzerland, Adamin is so far only known from Mürtschenalp in the canton of Glarus and the Gosan mine near Saint-Luc VS in the canton of Valais. another location on the Reckibach in the Binn valley has not yet been confirmed.
Is known, due to exceptional Adaminfunde the "Mina Ojuela" (English Ojuela Mine ) in Mapimí in the Mexican state of Durango, where lined with green and violet rare Adaminkristallen drusen were detected up to 7 cm in diameter.
Other locations include Algeria, Argentina, Australia, China, France, Bulgaria, Greece, Iran, Ireland, Italy, Japan, Kazakhstan, the Democratic Republic of the Congo, Morocco, Mexico, Namibia, Poland, Russia, Serbia, Zimbabwe, Spain, South Africa, the Czech Republic in the United Kingdom and the United States of America.
See also
literature
- C. Friedel, GA Daubrée: Sur l'adamine, nouvelle espèce minérale . In: Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences . tape 62 , 1866, pp. 692–695 (French, rruff.info [PDF; 285 kB ; accessed on January 6, 2020]).
- 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. 646 .
- Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 629 (first edition: 1891).
Web links
- Mineral Atlas: Adamin (Wiki)
- Adamite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF)(English).
- American-Mineralogist-Crystal-Structure-Database - Adamite. In: rruff.geo.arizona.edu. (English).
Individual evidence
- ↑ a b c 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 January 6, 2020 .
- ↑ 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. 444 .
- ↑ a b c d e Adamite . 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 January 6, 2020]).
- ↑ a b c d e f g Adamite. In: mindat.org. Hudson Institute of Mineralogy, accessed January 6, 2020 .
- ↑ Lloyd W. Staples: Adamite from Gold Hill, Tooele Co., Utah . In: The American Mineralogist . tape 20 , no. 5 , 1935, pp. 371 ( minsocam.org [PDF; 320 kB ; accessed on January 6, 2020]).
- ↑ Catalog of Type Mineral Specimens - A. (PDF 85 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed January 6, 2020 .
- ↑ 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 January 6, 2020 .
- ↑ David Barthelmy: Adamite MineralData. In: webmineral.com. Retrieved January 6, 2020 .
- ↑ C. Friedel, GA Daubrée: Sur l'adamine, nouvelle espèce minérale . In: Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences . tape 62 , 1866, pp. 694 (French, rruff.info [PDF; 285 kB ; accessed on January 6, 2020]).
- ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (= Dörfler Natur ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 161 .
- ↑ Find location list for Adamin in the Mineralienatlas and Mindat , accessed on January 6, 2020.