Dundasite
| Dundasite | |
|---|---|
 |
|
| General and classification | |
| chemical formula |
|
|
Mineral class (and possibly department) |
Carbonates and nitrates (formerly carbonates, nitrates and borates) |
|
System no. to Strunz and to Dana |
5.DB.10 ( 8th edition : V / E.08) 16b.02.01.01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m |
| Space group | Pbnm (No. 62, position 3) |
| Lattice parameters | a = 9.08 Å ; b = 16.37 Å; c = 5.62 Å |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 2 |
| Density (g / cm 3 ) | measured: 3.10 to 3.55; calculated: 3.716 |
| Cleavage | completely after {010} |
| colour | colorless to white, rarely light green or light blue |
| Line color | White |
| transparency | transparent |
| shine | Glass gloss, silk gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.603 n β = 1.716 n γ = 1.750 |
| Birefringence | δ = 0.147 |
| Optical character | biaxial negative |
| Axis angle | 2V = 30 to 40 ° (measured); 54 ° (calculated) |
Dundasite is a mineral from the mineral class of " carbonates and nitrates " with the chemical composition PbAl 2 [(OH) 4 | (CO 3 ) 2 ] · H 2 O and is therefore chemically a water-containing lead - aluminum carbonate with additional hydroxide ions .
Dundasite crystallizes in the orthorhombic crystal system and develops needle-like crystals stretched along the c-axis , which are usually arranged in radial to spherical mineral aggregates or matted crusts. The crystals themselves are colorless and transparent and their surfaces have a glass-like sheen . In aggregate form, the mineral appears white due to multiple refraction and shows a silk-like shimmer. Dundasite can also take on a light green or light blue color through foreign admixtures.
Etymology and history
Dundasit was first found in 1893 in the "Adeleit Mine" near Dundas (Zeehan District) in Tasmania . The first descriptor William Frederick Petterd (1849-1910), an amateur collector and publicist of numerous important lists on the mineralogy of Tasmania, named the mineral after its type locality .
classification
In the now outdated, but still in use, 8th edition of the mineral classification according to Strunz , the dundasite belonged to the common mineral class of "carbonates, nitrates and borates" and there to the department of "hydrous carbonates with foreign anions ", where together with ankylite (La ) , Ankylit- (Ce) , barstowite , Calcio-Ankylit- (Ce) , Calcio-Ankylit- (Nd) , Dresserit , Gysinit- (Nd) , Hydrodresserit , Kamphaugit- (Y) , Kochsándorit , Montroyalit , Petterdit , Strontiodresserit and Thomasclarkit- (Y) formed the independent group V / E.08 .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), assigns the Dundasite to the class of "carbonates and nitrates" (the borates form a separate class here) and there also to the department of “Water-containing carbonates with foreign anions” (carbonates with other anions, with H 2 O). This section is, however, further subdivided according to the size of the cations involved , so that the mineral can be found according to its composition in the sub-section "with large and medium-sized cations", where it is only found together with dresserite, kochsándorite, montroyalite, petterdite and strontiodresserite "Dresseritgruppe" with the system no. 5.DB.10 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the dundasite to the class of "carbonates, nitrates and borates" and there in the department of "16b carbonates - hydroxyl or halogen", like the outdated Strunz system. Here he is together with dresserite, strontiodresserite, petterdit and kochsándorite in the unnamed group 16b.02.01 within the subdivision " carbonates - hydroxyl or halogen with (A) m (B) n (XO 3 ) p Z q x (H 2 O)" , with (m + n): p = 3: 2 “.
Crystal structure
Dundasite crystallizes orthorhombically in the space group Pbnm (space group no. 62, position 3) with the lattice parameters a = 9.08 Å , b = 16.37 Å and c = 5.62 Å as well as four formula units per unit cell .
Education and Locations
Dundasit is a typical secondary mineral , which is in the oxidation zone of lead - deposits formed. Begleitminerale mostly Krokoit , azurite and malachite , as well Beudantit , Cerussite , Duftit , gibbsite , Mimetitesit , Plattnerit and Pyromorphite .
So far, the mineral has been found in the following locations: In addition to its type locality Dundas, it is also near Williamsford on Tasmania in Australia; Liege in Belgium; Guangxi in the People's Republic of China; Lower Saxony (Harz), North Rhine-Westphalia (Sauerland, Siegerland), Rhineland-Palatinate (Nothweiler, Bad Ems, Rheinbreitbach); Alsace , Aquitaine , Languedoc-Roussillon , Provence-Alpes-Côte d'Azur and Rhône-Alpes in France; Attica in Greece; England , Scotland and Wales in Great Britain; Galway and Tipperary in Ireland; Lombardy , Sardinia , Tuscany and Veneto in Italy; Oshikoto in Namibia; on the North Island in New Zealand; Carinthia , Salzburg and Styria in Austria; Moravia in the Czech Republic; Heves county in Hungary; as well as Nevada , New Jersey and New Mexico in the USA .
See also
literature
- WF Petterd: A catalog of the minerals known to occur in Tasmania, with notes on their distribution . In: Papers and Proceedings of the Royal Society of Tasmania for 1893 . 1894, p. 1–72 ( available online at rruff.info [PDF; 3.2 MB ; accessed on April 7, 2019]).
- G. Cocco, L. Fanfani, A. Nunzi, PF Zanazzi: The crystal structure of dundasite . In: Mineralogical Magazine . tape 38 , 1972, p. 564–569 ( available online at rruff.info [PDF; 311 kB ; accessed on July 27, 2017]).
- Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 583 (first edition: 1891).
Web links
- Mineral Atlas: Dundasite (Wiki)
- Dundasite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed April 7, 2019 .
- American-Mineralogist-Crystal-Structure-Database - Dundasite. In: rruff.geo.arizona.edu. Accessed April 7, 2019 .
Individual evidence
- ↑ 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. 315 (English).
- ↑ 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 .
- ↑ David Barthelmy: Dundasite Mineral Data. In: webmineral.com. Accessed April 7, 2019 .
- ↑ a b Dundasite . 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; 66 kB ; accessed on July 27, 2017]).
- ↑ a b c d e Dundasite. In: mindat.org. Hudson Institute of Mineralogy, accessed April 7, 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. 717 .
- ^ William D. Birch, Uwe Kolitsch, Thomas Witzke, Lutz Nasdala, Ralph S. Bottrill: Petterdite, the Cr-dominant analogue of dundasite, a new mineral species from Dundas, Tasmania, Australia and Callenberg, Saxony, Germany . In: The Canadian Mineralogist . tape 38 , no. 6 , 2000, pp. 1467–1476 , doi : 10.2113 / gscanmin.38.6.1467 (English, rruff.info [PDF; 1.6 MB ; accessed on April 7, 2019]).
- ↑ Find location list for Dundasit in the Mineralienatlas and Mindat