Cobaltite

• Cobalt gris
• éclatant cobalt
• Cobalt gloss or gloss cobalt
• Kobaltin or Cobaltite
• White smaltite

Cobaltite, outdated also known as cobalt gloss, gloss cobalt, Kobaltin or cobaltite, is a commonly occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the orthorhombic crystal system with the chemical formula CoAsS, that consists of equal parts of cobalt, arsenic and sulfur.

Cobaltite developed pseudocubic or pseudooctahedral crystals up to 8 cm in size, similar to those of pyrite and its crystal faces may be striated similar to this mineral. Besides crystals are also found granular to massive aggregates. The mineral is opaque in any form, pointing to unweathered crystal faces a strong metallic luster. Fresh samples initially have a silver- white color with a tinge of reddish- violet, however, run after some time on the air reddish gray to.

Special Features

When heated in the blowpipe cobaltite are the enthaltete arsenic from arsenic as smoke. It forms a gray, weakly magnetic ball. The borax bead is colored dark blue after roasting by the cobalt. Soluble is cobaltite in hot nitric acid.

Etymology and history

As cobalt luster, the mineral was known to the miners of the Middle Ages and considered " bewitched by goblins ." Your appearance after the ore seemed to contain profitable metals that did not let himself be melted. Instead, it was because of the arsenic content from only when heated, toxic vapors ( Hüttenrauch ).

For the first time quantitatively analyzed and described as cobalt gloss was the mineral in 1797 by Martin Heinrich Klaproth. His up today valid name cobaltite (French: Cobaltine ) received the mineral in 1832 by François Sulpice Beudant, if, after its signature ingredient, the element cobalt, named. More firmly held by him are synonyms gris cobalt, cobalt éclatant, White smaltite.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the cobaltite belonged to the mineral class of " sulfides and sulfosalts " and then to the Department of " sulfides with the molar ratio of metal: sulfur, selenium, tellurium <1: 1 " where as he named was the " Cobaltitgruppe " with the other members Gersdorffite, Hollingworthit, Irarsit, Jolliffeit, Kalungait, Milotait, Platarsit, Tolovkit, Ullmannite and Willyamit.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the cobaltite also in the class of " sulfides and sulfosalts " and there in the department of " metal sulfides with M: S ≤ 1: 2 ". This division, however, is further subdivided by the exact molar ratio and the conditions prevailing in the interconnect metals, so that the mineral according to its composition in the subsection "M: S = 1: 2, with Fe, Co, Ni, PGE, etc. " to find is where it together with Changchengit, Gersdorffite, Hollingworthit, Irarsit, Jolliffeit, Kalungait, Maslovit, Mayingit, Michenerit, Milotait, Padmait, Platarsit, Testibiopalladit, Tolovkit, Ullmannite and Willya the " Gerdorffitgruppe " with the system no. 2.EB.25 forms.

The classification of minerals according to Dana assigns the cobaltite in the class of " sulfides and sulfosalts " and then in the Department of " sulfide minerals ." Here he is named the " Cobaltitgruppe ( Cubic or pseudocubic crystals) " with the system no. 02.12.03 and the other members Gersdorffite, Ullmannite, Willyamit, Tolovkit, Platarsit, Irarsit, Hollingworthit, Jolliffeit, Padmait, Michenerit, Maslovit, Testibiopalladit, Changchengit, Milotait and Kalungait within the subdivision " sulfides - tellurides and selenides, including - with the composition AmBnXp, with (m n): p = 1:2 find ".

Education and Locations

Cobaltite forms as a secondary mineral under hydrothermal conditions at high temperatures. The mineral is found as Einsprengung or vein in metamorphic rocks. It is often associated with cobalt -nickel sulphides and arsenides, and magnetite, sphalerite, chalcopyrite, skutterudite, allanite, zoisite, scapolite, titanite and calcite ( in Tunaberg, Sweden) socialized.

Worldwide, cobaltite so far (as of 2012) are detected at around 750 localities. Important localities are Tunaberg and vein at Askersund in Sweden and Skudderud at Modum in Norway, often find cobaltite in Cornwall (England), Ontario ( Canada ), Australia and Morocco. In Germany you will find cobaltite among others in the Ore Mountains, resin, and the winning country. Besides the described many smaller finds are known.

Crystal structure

Cobaltite crystallized in the orthorhombic crystal system, space group Pca21 ( Raumgruppen-Nr. 29) the lattice parameters a = 5.59 Å, b = 5.58 Å and c = 5.58 Å and four formula units per unit cell.

Use

Cobaltite is an important raw material for the extraction of cobalt and its compounds.