Ruthenic arsenite

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Ruthenic arsenite
General and classification
chemical formula (Ru, Ni) As
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.CC.15 ( 8th edition : II / C.20)
08/02/17/01
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol mmm
Space group Pnma
Lattice parameters a  = 5.628  Å ; b  = 3.239 Å; c  = 6.184 Å
Formula units Z  = 4
Physical Properties
Mohs hardness 6 to 6.5
Density (g / cm 3 ) 10.0
Cleavage Please complete!
colour pale orange-brown to brown-gray
Line color Please complete!
transparency opaque
shine Please complete!

Ruthenarsenite is a very rarely occurring mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the orthorhombic crystal system with the chemical composition (Ru, Ni) As and forms up to 100 μm large inclusions in rutheniridosmin of pale orange-brown to brown-gray color.

Etymology and history

The mineral was first found in 1974 by DC Harris in the type locality, the Waria River in the province of Oro in Papua New Guinea . It is named after its composition from the elements ruthenium and arsenic .

classification

In the Strunz system , ruthenium arsenite is counted among the sulfides and sulfosalts. After the 8th edition it forms together with Breithauptit , Cherepanovit , Freboldit , Hexatestibiopanickelit , Kotulskit , Nickelin , Langisit , Polarit , Sederholmit , Sobolevskit , Sorosit , Stumpflit and Sudburyit a subgroup of the sulphides with a ratio of metal to sulfur, selenium or tellurium from 1: 1. In the 9th Edition it forms with Cherepanovit, Modderit and Westerveldit a subgroup of the compounds of metal sulfides with iron, cobalt, nickel, etc., and a ratio of 1: 1.

In the Dana system , it forms with cherepanovite a subgroup of sulfides, selenides and tellurides with the composition A m B n X p , with (m + n): p = 1: 1.

Education and Locations

Ruthenarsenite is formed as an injection in natural osmium - iridium- ruthenium alloys and in ultramafitites . It is associated with rutheniridosmin , irarsite and iridarsenite .

So far (as of June 2010) only five locations are known of the very rare mineral. In addition to the type locality, these are Amdo in the autonomous region of Tibet ( China ), Lake Chankasee in Russia , the Onverwacht mine near Mashishing in the Bushveld complex , South Africa and Goodnews Bay in the US state of Alaska .

Crystal structure

Ruthenarsenite crystallizes in the orthorhombic crystal system in the space group Pnma with the lattice parameters a  = 5.628  Å ; b  = 3.239 Å and c  = 6.184 Å as well as four formula units per unit cell . This is information for artificially produced ruthenium arsenide.

See also

Individual evidence

  1. ↑ a b Ruthenarsenit in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101.
  2. ↑ a b Ruthenarsenite at mindat.org (engl.)
  3. ^ New Dana Classification of Sulfide Minerals
  4. ^ Ruthenarsenit in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101.

literature

  • Ruthenarsenite in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( pdf ).

Web links