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Sarkinite
General
CategoryArsenate minerals
Formula
(repeating unit)
Mn2(AsO4)(OH)
Strunz classification8.BB.15
Dana classification41.6.3.3
Crystal systemMonoclinic
Space groupSpace group: P21/a
Unit cella=12.7795(13) Å
b=13.6127(14) Å
c=10.2188(11) Å
β = 108.834(2)°
Z=16
Identification
ColorRed to yellow
Crystal habitTabular or granular
CleavageDistinct on {100}
FractureIrregular/Uneven, Conchoidal
Mohs scale hardness4–5
LusterGreasy
StreakRed to yellow
DiaphaneitySemitransparent
Density4.08 to 4.18 g/cm (measured)
Optical propertiesBiaxial (-)
Refractive indexnα=1.793, nβ=1.807, nγ=1.809
Birefringenceδ = 0.016
PleochroismWeak
2V angle83° (measured)
Dispersionr > v or r < v
Absorption spectraX > Z > Y
SolubilityReadily soluble in dilute acids

Sarkinite, synonymous with chondrarsenite and polyarsenite, is a mineral with formula Mn2(AsO4)(OH). The mineral is named for the Greek word σάρκιυος, meaning made of flesh, for its red color and greasy luster. The mineral was first noted in Sweden in 1865 as chondrarsenite, though not identified as Sarkinite until 1885.

Description

Sarkinite is red to yellow in color. It occurs as thick tabular crystals, short prismatic crystals, or has a granular habit. Sarkinite sometimes aggregates into a roughly spherical shape. Sarkinite is a member of the Wagnerite Group.

The mineral occurs in manganese-rich lenses in quartzitic chlorite schists, methamorphosed zinc ore bodies, and rarely in metamorphosed FeMn orebodies.

Structure

Sarkinite is isostructural with triploidite and wolfeite and is a dimorph of eveite. The crystal structure consists of MnO4(OH)2 octahedra, MnO4(OH) trigonal bipyramids, and AsO4 tetrahedra.

History

In 1885, two similar minerals were discovered in Sweden. Polyarsenite was found in Grythyttan and named by Igelström for its high arsenic content. Sarkinite was discovered in Pajsberg, Persberg, and named by A. Sjögren after the Greek word σάρκιυος, meaning made of flesh, in reference to the blood-red color and greasy luster. It was considered likely that the two minerals were identical. A study in 1980 showed that polyarsenite and chondrarsenite, discovered in 1865, were in fact both sarkinite.

Distribution

As of 2012, sarkinite has been found in Austria, France, Italy, Japan, Kazakhstan, Romania, Sweden, Switzerland, and the United States of America.

Association

Sarkinite has been found in association with:

Harstigen mine, Sweden

Sjö mine, Sweden

Ködnitz Valley, Austria

Falotta mine, Switzerland

Sterling Hill, New Jersey, USA

References

  1. ^ "Sarkinite". Mindat. Retrieved May 28, 2012.
  2. ^ "Sarkinite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved May 30, 2012.
  3. "Sarkinite". Webmineral. Retrieved May 29, 2012.
  4. Halenius, p. 113.
  5. Dal Negro, p. 246.
  6. Smithsonian Institution (1886). Annual Report of the Board of Regents of the Smithsonian Institution Showing the Operations, Expenditures, and Condition of the Institution to July, 1885 (Report). Government Printing Office. p. 701. {{cite report}}: Cite has empty unknown parameter: |coauthors= (help)
  7. Dunn, Pete J. (1980). "On the composition of some sarkinites" (PDF). Mineralogical Magazine. 43 (329): 681. Retrieved May 29, 2012. {{cite journal}}: Unknown parameter |month= ignored (help)

Bibliography

External links

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