Brucite

Brucite
General
CategoryOxide mineral
Formula
(repeating unit)
Mg(OH)2
IMA symbolBrc[1]
Strunz classification4.FE.05
Crystal systemTrigonal
Crystal classHexagonal crystal family (3m)
H-M symbol: (3 2/m)
Space groupP3m1
Unit cella = 3.142(1) Å, c = 4.766(2) Å; Z = 1
Identification
ColorWhite, pale green, blue, gray; honey-yellow to brownish red
Crystal habitTabular crystals; platy or foliated masses and rosettes – fibrous to massive
CleavagePerfect on {0001}
FractureIrregular
TenacitySectile
Mohs scale hardness2.5 to 3
LusterVitreous to pearly
StreakWhite
DiaphaneityTransparent
Specific gravity2.39 to 2.40
Optical propertiesUniaxial (+)
Refractive indexnω = 1.56–1.59
nε = 1.58–1.60
Birefringence0.02
Other characteristicsPyroelectric
References[2][3][4]

Brucite is the mineral form of magnesium hydroxide, with the chemical formula Mg(OH)2. It is a common alteration product of periclase in marble; a low-temperature hydrothermal vein mineral in metamorphosed limestones and chlorite schists; and formed during serpentinization of dunites. Brucite is often found in association with serpentine, calcite, aragonite, dolomite, magnesite, hydromagnesite, artinite, talc and chrysotile.

It adopts a layered CdI2-like structure with hydrogen-bonds between the layers.[5]

  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. ^ Brucite on Mindat.org
  3. ^ Handbook of Mineralogy
  4. ^ Brucite on Webmineral
  5. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.