Solid phase
Official name
Synthetic amorphous silica
Secondary names
fused quartz; silica
CAS number
7631-86-9
Type
Family
covalent network solid
Class
glass
Compound type
silicate
Chemical composition
Formula
$SiO_2$
Chemical formula
SiO2
Elemental formula
Si O2
Isotope mixture type
terrestrial abundance
6.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$Si$ Silicon element 1 0.3333333333333333 1 pure main
$O$ Oxygen element 2 0.6666666666666666 1 pure main
Class
glasses (12)
Type
two non-metal atoms glasses (12.02)
Polymorphs
Phase name
amorphous silica
Phase type
glassy
Crystal system
amorphous
Molar mass
60.084 $g/mol$
Density
2.196 $g/cm^3$
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid liquid 1713 °C (1986 K)
Refringence type
isotropic
Refraction index $n_{\alpha}$
1.458
Pure color
colorless
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