Constituent
Name
Quartz
Class
silicate mineral
Compound type
tektosilicate
Comments
alpha-Quartz: exists with 2 chiral space groups: P3(2)21 and P3(1)21
Relevance
main - major
Arrangement
single phase
Abundance comments
Abundant
Formula
$SiO_2$
Chemical formula
SiO2
Elemental formula
Si O2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Si$ Silicon element 1 constituent element main
$O$ Oxygen element 2 constituent element main
Composition comments
Common impurities: traces of Al,Fe,Ti,Li,Ca,Mg, etc
Chemical bonds
  Bond Number
$\geq Si-O-$ 4
Oxides
Formula $SiO_{2}$
Mass fraction (%) 100.0

Strunz

Class
oxides - hydroxides - arsenites (04)
Division
metal:oxygen = 1:2 and similar (04.D)
Family
with small cations: Silica family (04.DA)
Code
04.DA.05

Dana

Major class
silicates (VIII)
Class
tectosilicate Si tetrahedral frameworks (75)
Type
SiO2 with [4] coordinated Si (75.01)
Phase type
crystalline
Crystal system
trigonal
Composition order
ordered
Comments
Quartz forms left- and right-handed crystals. Space groups: $P3_121$ (right) and $P3_221$ (left)
Molar mass
60.08 $g/mol$
Density
2.60 - 2.65 $g/cm^3$
Refringence type
uniaxial
Refringence sign
positive
Birefringence
0.009
Refraction index $n_{\alpha}$
1.543 - 1.545
Refraction index $n_{\beta}$
1.552 - 1.554
Color
colorless, brown, violet, gray, yellow
Diaphaneity
transparent
Luster
vitreous