පළිඟු

පළිඟු
Quartz crystal cluster from Tibet
General
Category	Silicate mineral
රසායනික සූත්‍රය	SiO₂
Strunz classification	04.DA.05
Dana classification	75.01.03.01
Crystal symmetry	Trigonal 32
Unit cell	a = 4.9133 Å, c = 5.4053 Å; Z=3
Identification
පාට / පැහැය	Colorless through various colors to black
Crystal habit	6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive
Crystal system	α-quartz: trigonal trapezohedral class 3 2; β-quartz: hexagonal 622
Twinning	Common Dauphine law, Brazil law and Japan law
Cleavage	{0110} Indistinct
Fracture	Conchoidal
Tenacity	කැඩෙනසුළු
Mohs scale hardness	7 – lower in impure varieties (defining mineral)
Luster	Vitreous – waxy to dull when massive
Streak	සුදු
Diaphaneity	Transparent to nearly opaque
Specific gravity	2.65; variable 2.59–2.63 in impure varieties
Optical properties	Uniaxial (+)
Refractive index	n_ω = 1.543–1.545 n_ε = 1.552–1.554
Birefringence	+0.009 (B-G interval)
Pleochroism	නැත
Melting point	1670 °C (β tridymite) 1713 °C (β cristobalite)
Solubility	Insoluble at STP; 1 ppm_mass at 400 °C and 500 lb/in² to 2600 ppm_mass at 500 °C and 1500 lb/in²
Other characteristics	Piezoelectric, may be triboluminescent, chiral (hence optically active if not racemic)
References

වර්ග (පාට අනුව)

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
Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W. and Nichols, Monte C. (ed.). "Quartz". Handbook of Mineralogy (PDF). Vol. III (Halides, Hydroxides, Oxides). Chantilly, VA, US: Mineralogical Society of America. ISBN 0962209724.{{cite book}}: CS1 maint: multiple names: editors list (link)
Quartz. Mindat.org. Retrieved on 2013-03-07.
Quartz. Webmineral.com. Retrieved on 2013-03-07.
Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20 ed.). ISBN 0-471-80580-7.{{cite book}}: CS1 maint: multiple names: authors list (link)