Jump to content

Quartz

Lát'ọwọ́ Wikipedia, ìwé ìmọ̀ ọ̀fẹ́
Quartz
Quartz crystal cluster from Tibet
General
CategoryOxide mineral
Chemical formulaSilica (silicon dioxide, SiO2)
Strunz classification04.DA.05
Dana classification75.01.03.01
Identification
ColorColorless through various colors to black
Crystal habit6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive
Crystal systemα-quartz: trigonal trapezohedral class 3 2; β-quartz: hexagonal 622[1]
TwinningCommon Dauphine law, Brazil law and Japan law
Cleavage{0110} Indistinct
FractureConchoidal
TenacityBrittle
Mohs scale hardness7 - lower in impure varieties
LusterVitreous - waxy to dull when massive
StreakWhite
DiaphaneityTransparent to nearly opaque
Specific gravity2.65; variable 2.59 - 2.63 in impure varieties
Optical propertiesUniaxial (+)
Refractive indexnω = 1.543 - 1.545 nε = 1.552 - 1.554
Birefringence+0.009 (B-G interval)
PleochroismNone
Melting point1670 °C (β tridymite) 1713 °C (β cristobalite)[1]
Solubility1 ppmmass at 400 °C and 500 lb/in2 to 2600 ppmmass at 500 °C and 1500 lb/in2[1]
Other characteristicsPiezoelectric, pyroelectric, may be triboluminescent
References[2][3][4][5]

Quartz


  1. 1.0 1.1 1.2 Deer, W. A., R. A. Howie and J. Zussman, An Introduction to the Rock Forming Minerals, Logman, 1966, pp. 340-355 ISBN 0-582-44210-9
  2. Handbook of Mineralogy. Quartz
  3. Mindat. Quartz
  4. Webmineral. Quartz
  5. Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20 ed.). ISBN 0-471-80580-7.