Constituent
- Name
- Quartz
- IMA name
- alpha-Quartz
- Class
- silicate mineral
- Compound type
- tektosilicate
- Comments
-
ome grains are altered by ferric oxides
alpha-Quartz: exists with 2 chiral space groups: P3(2)21 and P3(1)21
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Abundance comments
- Some grains may contain products of alteration by ferric oxides
- Formula
- $SiO_2$
- Chemical formula
- SiO2
- Elemental formula
- Si O2
- Isotope mixture type
- terrestrial abundance
- 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)
- Texture
- polycrystalline
- 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