Sarkinite

Sarkinite
General
CategoryArsenate minerals
Formula
(repeating unit)		Mn2(AsO4)(OH)[1]
IMA symbolSrk[2]
Strunz classification8.BB.15[1]
Dana classification41.6.3.3[1]
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP2m[1]
Unit cella = 12.7795(13) Å
b = 13.6127(14) Å
c = 10.2188(11) Å
β = 108.834(2)°; Z = 16[1]
Identification
ColorRed to yellow[1]
Crystal habitTabular[3] or granular[1]
CleavageDistinct on {100}[1]
FractureIrregular/Uneven, Conchoidal[1]
Mohs scale hardness4–5[1]
LusterGreasy[1]
StreakRed to yellow[1]
DiaphaneitySemitransparent[4]
Density4.08 to 4.18 g/cm3 (measured)[1]
Optical propertiesBiaxial (−)[1]
Refractive indexnα=1.793, nβ=1.807, nγ=1.809[1]
Birefringenceδ = 0.016[1]
PleochroismWeak[1]
2V angle83° (measured)[1]
Dispersionr > v or r < v[1]
Absorption spectraX > Z > Y[1]
SolubilityReadily soluble in dilute acids[1]

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.[1]

The mineral occurs in manganese-rich lenses in quartzitic chlorite schists, metamorphosed zinc ore bodies, and rarely in metamorphosed Fe–Mn ore bodies.[4]

Structure

Sarkinite is isostructural with triploidite and wolfeite[1] and is a dimorph of eveite.[5] The crystal structure consists of MnO4(OH)2 octahedra, MnO4(OH) trigonal bipyramids, and AsO4 tetrahedra.[6]

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.[7] A study in 1980 showed that polyarsenite and chondrarsenite, discovered in 1865, were in fact both sarkinite.[8]

Distribution

As of 2012, sarkinite has been found in Austria, France, Italy, Japan, Kazakhstan, Romania, Sweden, Switzerland, and the United States.[1]

Association

Sarkinite has been found in association with:[4]

Harstigen mine, Sweden

Sjö mine, Sweden

Ködnitz Valley, Austria

Falotta mine, Switzerland

Sterling Hill, New Jersey, US

References

  1. ^ a b c d e f g h i j k l m n o p q r s t u v w x "Sarkinite". Mindat. Retrieved May 28, 2012.
  2. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  3. ^ "Sarkinite". Webmineral. Retrieved May 29, 2012.
  4. ^ a b c "Sarkinite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved May 30, 2012.
  5. ^ Halenius, p. 113.
  6. ^ Dal Negro, p. 246.
  7. ^ 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.
  8. ^ Dunn, Pete J. (March 1980). "On the composition of some sarkinites" (PDF). Mineralogical Magazine. 43 (329): 681. Bibcode:1980MinM...43..681D. doi:10.1180/minmag.1980.043.329.22. S2CID 129159875. Retrieved May 29, 2012.

Bibliography

Media related to Sarkinite at Wikimedia Commons