Sursassite

Sursassite
General
Category Sorosilicate
Formula
(repeating unit)
Mn2+2Al3(SiO4)(Si2O7)(OH)3
Strunz classification 9.BG.15
Crystal system Monoclinic
Identification
Color Red-brown to copper-red
Crystal habit Botryoidal
Crystal symmetry Monoclinic - prismatic
H-M Symbol (2/m)
Space group: P 21/m
Cleavage [101] Distinct
Mohs scale hardness 3
Luster Silky, Dull
Streak yellow-brown
Diaphaneity Translucent
Density 3.256
Optical properties Biaxial
Refractive index 1.73 to 1.76
Birefringence 0.030
Pleochroism

Strong; X = Z = colorless to pale yellow; Y = deep

golden brown.
Dispersion r > v
References [1][2]

Sursassite is a sorosilicate mineral. It was first discovered in 1926.[3] It was first found in the Sursass (Oberhalbstein), a district of Graubünden, Switzerland. It is generally found in deposits of metamorphosed manganese.[4]

Notes

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


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