පඩියං
| Topaz | |
|---|---|
 Facet Cut Topaz Gemstones in various colors | |
| General | |
| Category | Silicate mineral |
| රසායනික සූත්රය | Al2SiO4(F,OH)2 |
| Strunz classification | 9.AF.35 |
| Crystal symmetry | Orthorhombic dipyramidal H-M symbol: (2/m 2/m 2/m) Space group: Pbnm |
| Unit cell | a = 4.65 Å, b = 8.8 Å, c = 8.4 Å; Z = 4 |
| Identification | |
| පාට / පැහැය | Colorless (if no impurities), blue, brown, orange, gray, yellow, green, pink and reddish pink |
| Crystal habit | Prismatic crystals with faces striated parallel to long dimension; also columnar, compact, massive |
| Crystal system | Orthorhombic |
| Cleavage | [001] Perfect |
| Fracture | Subconchoidal to uneven |
| Mohs scale hardness | 8 (defining mineral) |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 3.49–3.57 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.606–1.629 nβ = 1.609–1.631 nγ = 1.616–1.638 |
| Birefringence | δ = 0.010 |
| Pleochroism | Weak in thick sections X = yellow; Y = yellow, violet, reddish; Z = violet, bluish, yellow, pink |
| Other characteristics | Fluorescent, short UV=golden yellow, long UV=cream |
| References | [1][2][3][4] |
- ^ Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7
- ^ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W. and Nichols, Monte C., ed. (1995). "Topaz". Handbook of Mineralogy (PDF). Vol. II (Silica, Silicates). Chantilly, VA, US: Mineralogical Society of America. ISBN 0-9622097-1-6. සම්ප්රවේශය December 5, 2011.
{{cite book}}: CS1 maint: multiple names: editors list (link) - ^ Topaz. Mindat.org. Retrieved on 2011-10-29.
- ^ Topaz. Webmineral.com. Retrieved on 2011-10-29.