Solid phase
Official name
Synthetic fayalite
Type
Family
ionic solid
Class
normal salt
Compound type
nesosilicate
Chemical composition
Formula
$(Fe^{2+})_2.SiO_4^{4-}$
Chemical formula
Fe2SiO4
Elemental formula
(Fe2+)2 Si (O-)4
Isotope mixture type
terrestrial abundance
6.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$Fe^{2+}$ Iron(II) cation element 2 0.6666666666666666 1 constituent cation main
$(SiO_4)^{4-}$ Silicate anion chemical function 1 0.3333333333333333 1 constituent anion main
Chemical functions
  Function Number
$(SiO_4)^{4-}$ 1
Chemical bonds
  Bond Number
$\geq Si-O^-$ 4
Class
normal salts (07)
Type
simple normal salts (07.01)
Equivalent mineral
Fayalite
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
dipyramidal
Crystal class symbol
mmm (D2h)
Crystal spacegroup
Pnma
Molar mass
203.78 $g/mol$
Density
4.39 $g/cm^3$
State NTP
solid
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.0420 - 0.0510
Refraction index $n_{\alpha}$
1.731 - 1.824
Refraction index $n_{\beta}$
1.76 - 1.864
Refraction index $n_{\gamma}$
1.773 - 1.875
Pure color
brown
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