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
Traces
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)
Group
Quartz group (75.01.03)
Code
75.01.03.01
Phase type
crystalline
Crystal system
trigonal
Crystal class
trapezohedral
Crystal class symbol
32 (D3)
Crystal spacegroup
P3(2)21
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