Newberyit

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Newberyit
Newberyite-38303.jpg
Newberyite crystal aggregate from the Skipton Caves, Aries Mountain, Corangamite Shire , Victoria, Australia (size 3.2 cm × 2.5 cm × 1.9 cm)
General and classification
chemical formula
  • Mg [PO 3 OH] • 3H 2 O
  • Mg [PO 3 (OH)] • 3H 2 O
  • MgH [PO 4 ] • 3H 2 O
Mineral class
(and possibly department) 		Phosphates, arsenates and vanadates
System no. to Strunz
and to Dana 		8.CE.10 ( 8th edition : VII / C.12)
39.01.06.01
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol orthorhombic-dipyramidal; 2 / m  2 / m  2 / m
Space group Pbca (No. 61)Template: room group / 61
Lattice parameters a  = 10.20  Å ; b  = 10.68 Å; c  = 10.01 Å
Formula units Z  = 8
Frequent crystal faces {001}, {010}, {100}, {021}, {102}, {111}
Physical Properties
Mohs hardness 3 to 3.5
Density (g / cm 3 ) measured: 2.10; calculated: [2.13]
Cleavage perfect after {010}, imperfect after {001}
Break ; Tenacity uneven; brittle
colour colorless, gray, gray-brown
Line color White
transparency transparent
shine Glass gloss
Crystal optics
Refractive indices n α  = 1.514
n β  = 1.518
n γ  = 1.533
Birefringence δ = 0.019
Optical character biaxial positive
Other properties
Chemical behavior slightly soluble in water, slightly soluble in hydrochloric acid

Newberyit is a rarely occurring minerals from the mineral class of "phosphates, arsenates, and vanadates" with the chemical composition Mg [PO 3 OH] · 3H 2 O and chemical point of a water-containing , basic magnesium - phosphate .

Newberyite crystallizes in the orthorhombic crystal system and develops tabular crystals up to about 2.5 cm in size with a glass-like sheen on the surfaces. But it also occurs in the form of powdery coatings and compact masses. In its pure form, Newberyite is colorless and transparent. However , it can also take on a gray to gray-brown color due to foreign admixtures.

Etymology and history

The mineral was first discovered in the Skipton Caves , a lava cave on Mount Widderin near the town of Skipton in the Corangamite Shire administrative region in the Australian state of Victoria . It was first described in 1879 by Gerhard vom Rath , who named the mineral after its discoverer James Cosmo Newbery (1843–1895).

The type material of the mineral is in the Muséum national d'histoire naturelle in Paris under the catalog no. 99.504 kept.

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the newberyite belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the department of "water-containing phosphates without foreign anions ", where together with Steigerite it belonged to the "newberyite -Steigerit Group "with the system no. VII / C.12 and the other members Kaňkit , Metaschoderit and Schoderit .

The 9th edition of Strunz's mineral systematics, which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns the Newberyite to the category of “Phosphates etc. without additional anions; with H 2 O “. However, this is further subdivided according to the relative size of the cations involved and the molar ratio of the phosphate, arsenate or vanadate complex (RO 4 ) to the water of crystallization content (H 2 O), so that the mineral is classified according to its composition in the sub-section "RO 4  : H 2 O = 1: 2.5 “can be found where it is the only member of the unnamed group 8.CE.10 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the newberyite to the class of "phosphates, arsenates and vanadates" and there in the department of "water-containing acidic phosphates, etc.". Here he is to be found as the only member of the unnamed group January 39, 2006 within the sub-section “ Hydrous acidic phosphates etc., A + [HXO 4 ] × x (H 2 O)”.

Chemism

The idealized (theoretical) composition of newberyite (Mg [PO 3 OH] · 3H 2 O) consists of 13.94% magnesium (Mg), 17.77% phosphorus (P), 64.24% oxygen (O) and 4 , 05% hydrogen (H). In oxidic form, this corresponds to 23.12% magnesium oxide (MgO), 40.71% diphosphorus pentoxide (P 2 O 5 ) and 36.17% water .

In the analysis of the mineral samples from the Skipton Caves type locality , however, small additions of iron (Fe) and manganese (Mn) were also detected.

Crystal structure

Newberyite crystallizes orthorhombically in the space group Pbca (space group no. 61) with the lattice parameters a  = 10.20  Å ; b  = 10.68 Å and c  = 10.01 Å and 8 formula units per unit cell . Template: room group / 61

The crystal structure is composed of insular Mg [6] - octahedra , the shared corners with PO 3 OH tetrahedron are linked to each other and parallel to form layers of the surface (010). These layers are only weakly connected to each other via hydrogen bonds , which is the reason for the complete cleavage according to {010}.

properties

With a Mohs hardness of 3 to 3.5, Newberyite is one of the medium-hard minerals that, like the reference mineral calcite (hardness 3), can be scratched with a copper coin.

Newberyite is difficult to dissolve in cold water, but easily soluble in dilute hydrochloric acid (1:10). When heated, the mineral loses its crystal water from a temperature of 130 ° C and dehydrates to MgHPO 4

Education and Locations

Gray newberyite aggregate from Skipton Caves, Australia (size: 3 cm × 2.6 cm × 1.8 cm)

Newberyite is formed from bat guano , i.e. from the excrement of bats through action on limestone . As Begleitminerale occur among other Biphosphammit , Hannayit , Monetit and struvite on.

As a rare mineral formation, Newberyite could only be detected at a few sites, with around 20 sites being documented so far (as of 2018). In addition to its type locality , the Skipton Caves in Corangamite Shire, the mineral occurred in Australia in the Starlight Cave in Warrnambool City, also in Victoria, as well as in the Moorba Cave at Jurien Bay in Dandaragan Shire and the Petrogale Cave near one Rest stop at Madura in Western Australia.

In Germany Newberyit could so far only on the dross halden the zinc smelter Friedrich Wilhelm (now Zinkhütte Birkengang ) at Birkengang about 10 km east-southeast of Aachen and the copper smelter Kall about 8 km southwest of Mechernich be found in North Rhine-Westphalia.

The only sites in Austria so far are the Stüblbau gold mine near Schellgaden in the municipality of Muhr in Salzburg and the lead-silver mine Roßblei (also Rossblei ) on the Eschachalm near Obertal (municipality of Schladming ) in Styria.

Other sites are found on the island of Ascension , which belongs to the British overseas territory , in Chile, Canada, Kenya, Malaysia, Poland, Russia, Slovakia, South Africa and in the US states of Hawaii, California and New Jersey.

See also

literature

  • G. vom Rath: Note sur deux nouveaux phosphates du guano . In: Bulletin de la Société Minéralogique de France . tape 2 , 1879, p. 79–82 (French, rruff.info [PDF; 177 kB ; accessed on January 1, 2019]).
  • RWE MacIvor: On Australian bat guano and some minerals occurring therein . In: The Chemical News . tape 55 , no. 1433 , 1887, pp. 215–216 (English, rruff.info [PDF; 312 kB ; accessed on January 1, 2019]).
  • D. June Sutor: The crystal and molecular structure of newberyite, MgHPO 4 · 3H 2 O . In: Acta Crystallographica . tape 23 , 1967, p. 418-422 , doi : 10.1107 / S0365110X67002889 (English).
  • F. Abbona, R. Boistelle, R. Haser: Hydrogen bonding in MgHPO 4 · 3H 2 O (newberyite) . In: Acta Crystallographica . B35, 1979, p. 2514-2518 , doi : 10.1107 / S0567740879009791 (English).
  • H. Bartl, M. Catti, W. Joswig, Giovanni Ferraris: Investigation of the crystal structure of newberyite, MgHPO4 · 3H2O, by single crystal neutron diffraction . In: Tschermaks Mineralogische und Petrographische Mitteilungen . tape 32 , 1983, pp. 187–194 , doi : 10.1007 / BF01081109 (English, available online at researchgate.net [accessed January 2, 2019]).

Web links

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

Individual evidence

  1. ↑ a b c d e f 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.  479 (English).
  2. ↑ a b c 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 .
  3. ↑ 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.  626 .
  4. ^ A b c David Barthelmy: Newberyite Mineral Data. In: webmineral.com. Accessed January 1, 2019 .
  5. ↑ a b c d e f g h Newberyite . 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; 508  kB ; accessed on January 1, 2019]).
  6. ↑ a b c d Newberyite. In: mindat.org. Hudson Institute of Mineralogy, accessed January 1, 2019 .
  7. ^ A b Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason , Abraham Rosenzweig: Dana's New Mineralogy . 8th edition. John Wiley & Sons, New York (et al.) 1997, ISBN 0-471-19310-0 , pp. 737-738 .
  8. ↑ Catalog of Type Mineral Specimens - N. (PDF 61 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, p. 7 , accessed August 29, 2019 .
  9. ↑ Newberyite - Number of localities. In: mindat.org. Hudson Institute of Mineralogy, accessed January 1, 2019 .
  10. ↑ Stefan Schorn and other authors: Finding place of zinc hut Friedrich-Wilhelm. In: mineralienatlas.de. Mineral Atlas - Fossil Atlas, accessed January 2, 2019 .
  11. ↑ Stefan Schorn and other authors: Find location Kupferhütte Kall. In: mineralienatlas.de. Mineral Atlas - Fossil Atlas, accessed January 2, 2019 .
  12. ↑ Find location list for Newberyit in the Mineralienatlas and Mindat