Moolooit

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Moolooit
Moolooite-91983.jpg
Moolooite from the Sarbaiskoe deposit (Sarbay Mine), Qostanai , Kazakhstan
General and classification
other names

IMA 1980-082

chemical formula Cu 2+ (C 2 O 4 ) n (H 2 O) (0.4 <n <0.7)
Mineral class
(and possibly department) 		Organic compounds / oxalates
System no. to Strunz
and to Dana 		10.AB.15 ( 8th edition : IX / A.01)
50.01.06.01
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol orthorhombic-dipyramidal; mmm
Room group (no.) Pnnm (No. 58)
Lattice parameters a  = 5.4  Å ; b  = 5.57 Å; c  = 2.54 Å
Formula units Z  = 1
Physical Properties
Mohs hardness Please complete!
Density (g / cm 3 ) calculated: 3.43
Cleavage Please complete!
colour turquoise green, blue green
Line color green
transparency translucent
shine Wax gloss to matt
Crystal optics
Refractive indices n α  = 1.570
n γ  = 1.950
Birefringence δ = 0.380

Moolooite is a very rarely occurring mineral from the mineral class of " organic compounds ". It crystallizes in the orthorhombic crystal system with the composition Cu 2+ (C 2 O 4 ) · n (H 2 O) where n is between 0.4 and 0.7. It is thus seen a chemically copper oxalate - hydrate . So far only microscopic crystals or coarse masses have been found. The greenish-blue, transparent mineral has a light blue line and a dull, waxy sheen.


Etymology and history

Moolooit was first found and described in 1986 by Richard M. Clarke and Ian R. Williams in the type locality Bunbury Well - Mooloo Downs Station , Murchison / Western Australia at these coordinates . The name of the mineral refers to this location.

classification

In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the Moolooite belonged to the mineral class of "organic compounds" and there to the department of "salts of organic acids", where together with Caoxit , Coskrenit- (Ce) , Glushinskit , Humboldtin , levinsonite (Y) , lindbergite , minguzzite , natroxalate , novgorodovaite , oxammite , stepanovite , weddellite , wheatleyite , whewellite , zhemchuzhnikovite and Zugshunstit- (Ce) the independent "oxalate group" with the system no. IX / A.01 formed.

The 9th edition of Strunz's mineral systematics, which has been in force since 2001 and is used by the International Mineralogical Association (IMA), also assigns Moolooit to the class of "organic compounds" and there to the department of "salts of organic acids". However, this division is further subdivided according to the acid on which the compounds are based, so that the mineral can be found according to its composition in the sub-division of "Oxalates", where it is the only member of the unnamed group 10.AB.15 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Moolooit to the class of "organic minerals" and there in the department of the same name. Here he is to be found as the only member in the unnamed group 50.01.06 within the subdivision " Salts of organic acids (oxalates) ".

Education and Locations

Moolooite is a secondary mineral that z. B. formed by the action of bird droppings on weathered copper ores. Antlerite , atacamite , barite , brochantite , chalcopyrite , covelline , digigenite , gypsum , jarosite , silica , libethenite , sampleite and whewellite were found as accompanying minerals at its type locality Bunbury Wels-Mooloo Downs Station .

In Germany, the mineral has so far appeared in the Clara mine near Oberwolfach in Baden-Württemberg and at the Iberg near Ilfeld on the southern edge of the Harz Mountains in Thuringia.

Other locations include Sainte-Marie-aux-Mines in France, the Sarbaiskoe deposit (Sarbay Mine) in the Qostanai area in Kazakhstan, near Gjersvik in the Norwegian municipality of Røyrvik and in the " Ahmeek Mine" in Keweenaw County (Michigan) and near San Rafael in Emery County, Utah, USA.

Crystal structure

Moolooite crystallizes orthorhombically , point group mmm, and in the space group Pnnm (space group no. 58) with the lattice parameters a  = 5.4  Å ; b  = 5.57 Å; c  = 2.54 Å; as well as one formula units per unit cell . The lattice constants a and b depend on the water content.

See also

Individual evidence

  1. ↑ a b c J. E. Chisholm, GC Jones, OW Purvis: Hydrated copper oxalte, moolooite, in lichens. In: Mineralogical Magazine. Vol. 51, 1987, pp. 715-718. (accessed May 21, 2012; PDF; 431 kB)
  2. ^ A b R. M. Clarke, IR Williams: Moolooite, a naturally occurring hydrated copper oxalate from western Australia. In: Mineralogical Magazine. Vol. 50, 1986, pp. 295-298. (accessed May 21, 2012; PDF; 277 kB).
  3. ^ Moolooite. (PDF; 64 kB). In: Handbook of Mineralogy.
  4. ^ Moolooite. In: Mindat.
  5. ↑ H. Schmittler: Structural principle of disordered copper (II) oxalate (CuC2O4.nH2O). In: monthly Deut. Akad. Wiss. Berlin. 10, 1968, pp. 581-604.

Web links

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