Sursassite is a sorosilicate mineral. It was first discovered in 1926.[4] It was first found in the Sursass (Oberhalbstein), a district of Graubünden, Switzerland. It is generally found in deposits of metamorphosed manganese.[5]

Sursassite
General
CategorySorosilicate
Formula
(repeating unit)
Mn2+2Al3(SiO4)(Si2O7)(OH)3
IMA symbolSs[1]
Strunz classification9.BG.15
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/m
Identification
ColorRed-brown to copper-red
Crystal habitBotryoidal
Cleavage[101] Distinct
Mohs scale hardness3
LusterSilky, Dull
Streakyellow-brown
DiaphaneityTranslucent
Density3.256
Optical propertiesBiaxial
Refractive index1.73 to 1.76
Birefringence0.030
PleochroismStrong; X = Z = colorless to pale yellow; Y = deep golden brown.
Dispersionr > v
References[2][3]

Notes

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  1. ^ 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.
  2. ^ Pierre Perroud. "Sursassite". Athena Mineralogy: Mineral Data.
  3. ^ Sursassite details from Handbook of Mineralogy
  4. ^ Schweizerische mineralogische und petrographische Mitteilungen (1926), 6, 376-380.
  5. ^ Barthelmy, Dave. "Sursassite Mineral Data". WebMineral. Retrieved 2009-03-17.