Constituent
- Name
- antigorite
- IMA name
- Antigorite
- Class
- silicate mineral
- Compound type
- phyllosilicate
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Formula
- $(Mg_x,Fe^{2+}_{1-x})_3.Si_2O_5(OH)_4 \ \ \ \ \ $ where $x=0-1$
- Chemical formula
- (Mg,Fe2+)3Si2O5(OH)4
- Elemental formula
- (Mg)2-3 (Fe2+)0-1 Si2 O9 H4
- Isotope mixture type
- terrestrial abundance
- Composition comments
- Common impurities: Ni, Al, Mn
- Oxides
-
Formula $MgO$ $FeO$ $SiO_{2}$ $H_{2}O$ Mass fraction (%) 30.15 17.92 39.95 11.98
Strunz
- Class
- silicates (09)
- Division
- phyllosilicate (09.E)
- Family
- with kaolinite layers composed of tetrahedral and octahedral nets (09.ED)
- Code
- 09.ED.15
Dana
- Major class
- silicates (VIII)
- Class
- phyllosilicate sheets of six-membered rings (71)
- Type
- with 1:1 layers (71.01)
- Group
- Serpentine group (-Antigorite- subgroup) (71.01.02a)
- Code
- 71.01.02a.01
- Phase type
- crystalline
- Crystal system
- monoclinic
- Crystal class
- domatic
- Crystal class symbol
- m (Cs)
- Crystal spacegroup
- Cm
- Molar mass
- 300.77 $g/mol$
- Density
- 2.5 - 2.6 $g/cm^3$
- Refringence type
- biaxial
- Refringence sign
- negative
- Birefringence
- 0-005 - 0.006
- Refraction index $n_{\alpha}$
- 1.555 - 1.567
- Refraction index $n_{\beta}$
- 1.560 - 1.573
- Refraction index $n_{\gamma}$
- 1.560 - 1.573
- Dispersion V
- weak, r > v
- Color
- white, green, green-blue, gray, bluish gray, brown, black
- Diaphaneity
- translucent to opaque
- Luster
- vitreous