Magnesite

Magnesite
Magnesite crystals from Brazil (11.4 × 9.2 × 3.6 cm)
General
CategoryCarbonate mineral
Formula
(repeating unit)
MgCO3
IMA symbolMgs[1]
Strunz classification5.AB.05
Crystal systemTrigonal
Crystal classHexagonal scalenohedral (3m)
H-M symbol: (3 2/m)
Space groupR3c
Identification
ColorColorless, white, pale yellow, pale brown, faintly pink, lilac-rose
Crystal habitUsually massive, rarely as rhombohedrons or hexagonal prisms
Cleavage[1011] perfect
FractureConchoidal
TenacityBrittle
Mohs scale hardness3.5–4.5
LusterVitreous
Streakwhite
DiaphaneityTransparent to translucent
Specific gravity3.0–3.2
Optical propertiesUniaxial (−)
Refractive indexnω=1.508 – 1.510 nε=1.700
Birefringence0.191
Fusibilityinfusible
SolubilityEffervesces in hot HCl
Other characteristicsMay exhibit pale green to pale blue fluorescence and phosphorescence under UV; triboluminescent
References[2][3][4][5]

Magnesite is a mineral with the chemical formula MgCO
3
(magnesium carbonate). Iron, manganese, cobalt, and nickel may occur as admixtures, but only in small amounts.

  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. ^ http://rruff.geo.arizona.edu/doclib/hom/magnesite.pdf Handbook of Mineralogy
  3. ^ http://www.mindat.org/min-2482.html Mindat.org
  4. ^ http://webmineral.com/data/Magnesite.shtml Webmineral data
  5. ^ Klein, Cornelis and Cornelius S. Hurlbut, Jr., Manual of Mineralogy, Wiley, 20th ed., p. 332 ISBN 0-471-80580-7