Bunsenite

Bunsenite, outdated nickel monoxide, electroless nickel (II ) oxide, is a very rare mineral from the mineral class of oxides and hydroxides. It crystallizes in the cubic crystal system and forms octahedral crystals of dark green color.

Etymology and history

Bunsenite was first found in 1858 in the Ore Mountains, close to Johann George Town and studied by C. Bergemann. He examined a mineral sample in which Nickelarsenide, native bismuth, but were also green, octahedral crystals present, which were insoluble in acids. He recognized that it was there, this is the already artificially produced by Robert Bunsen nickel monoxide ( nickel (II ) oxide ) would have to act. James Dwight Dana named the new mineral in 1868 finally after Bunsen bunsenite.

Classification

In the classification by Strunz bunsenite is counted among the oxides with a ratio of metal to oxygen of 2:1 or 1:1. After the 8th edition forms a group together with calcium oxide, Manganosit, Monteponit, Murdochit, periclase and wustite. In the 9th edition it forms with the same minerals except the Murdochit a subset of the oxides with a ratio of metal to oxygen of 1:1 and small to medium-sized cations ( Periklasgruppe ).

In the classification by Dana it forms with calcium oxide, Manganosit, Monteponit, periclase, wustite and Hongquiit the Periklasgruppe, a subgroup of the simple oxides with a cation charge of 2 .

Education and Locations

Bunsenite forms in nickel ores under hydrothermal conditions at about 730 ° C and less than 2000 bar through metamorphosis. Depending on the locality, it is associated with bismuth, Annabergite, Aerugit and Xanthiosit or Liebenbergit, Trevorit, Violarit, Millerite, Gaspeit, Nimit and Bonaccordit.

It is known only to a small number of localities. In addition to the type locality finds from Karasjok in Norway, the Orenburg Oblast in Russia and Bon Accord and Morokweng in South Africa are known.

Crystal structure

Bunsenite crystallizes in the cubic crystal system with space group Pm3m with lattice parameters a = 4.1769 Å and four formula units per unit cell ( sodium chloride structure).