Mineral phase
IMA name
Orthochrysotile
Secondary names
Asbestos
Class
silicate mineral
Compound type
phyllosilicate
Comments
Polytype of Chrysotile, unknown crystal structure
Formula
$Mg_3.Si_2O_5(OH)_4$
Chemical formula
Mg3Si2O5(OH)4
Elemental formula
Mg3 Si2 O9 H4
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mg$ Magnesium element 3 constituent element main
$Si$ Silicon element 2 constituent element main
$O$ Oxygen element 9 constituent element main
$H$ Hydrogen element 4 constituent element main
Composition comments
Common impurities: Al, $Fe_{3+}$, $Fe_{2+}$, $Cr_{3+}$, Mn, Ni, Ti, Ca
Chemical functions
  Function Number
$(OH)^-$ 4
Chemical bonds
  Bond Number
$O^--H$ 1
Oxides
Formula $MgO$ $SiO_{2}$ $H_{2}O$
Mass fraction (%) 43.63 43.37 13.0

Strunz

Class
silicates (09)
Division
phyllosilicate (09.E)
Family
Phyllosilicates with kaolinite layers (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 (Chrysotile subgroup) (71.01.02d)
Code
71.01.02d.02
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
unknown
Crystal class symbol
unknown
Crystal spacegroup
unknown
Molar mass
277.11 $g/mol$
Density
2.53 - 2.65 $g/cm^3$
State NTP
solid
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.002 - 0.008
Refraction index $n_{\alpha}$
1.545 - 1.569
Refraction index $n_{\beta}$
1.546 - 1.569
Refraction index $n_{\gamma}$
1.553 - 1.571
Dispersion V
relatively weak
Pure color
colorless
Color
colorless, yellow, green, gray, gray brown, brownish
Diaphaneity
translucent to opaque
Luster
silky