| තෝරමල්ලි | |
|---|---|
Bi-colored tourmaline crystal, 0.8 inches (2 cm) long | |
| General | |
| Category | Cyclosilicate |
| රසායනික සූත්රය | (Ca,K,Na,[])(Al,Fe,Li,Mg,Mn)3(Al,Cr, Fe,V)6 (BO3)3(Si,Al,B)6O18(OH,F)4 |
| Identification | |
| පාට / පැහැය | Most commonly black, but can range from brown, violet, green, pink, or in a dual-colored pink and green. |
| Crystal habit | Parallel and elongated. Acicular prisms, sometimes radiating. Massive. Scattered grains (in granite). |
| Crystal system | Trigonal |
| Cleavage | Indistinct |
| Fracture | Uneven, small conchoidal, brittle |
| Mohs scale hardness | 7–7.5 |
| Luster | Vitreous, sometimes resinous |
| Streak | White |
| Specific gravity | 3.06 (+.20 -.06) |
| ඝනත්වයy | 2.82–3.32 |
| Polish luster | Vitreous |
| Optical properties | Double refractive, uniaxial negative |
| Refractive index | nω=1.635–1.675, nε=1.610–1.650 |
| Birefringence | -0.018 to -0.040; typically about .020 but in dark stones it may reach .040 |
| Pleochroism | typically moderate to strong Red Tourmaline: Definite; dark red,light red Green Tourmaline: Strong; dark green, yellow-green Brown Tourmaline: Definite; dark brown, light brown Blue Tourmaline: Strong; dark blue, light blue |
| Dispersion | .017 |
| Ultraviolet fluorescence | pink stones—inert to very weak red to violet in long and short wave |
| Absorption spectra | a strong narrow band at 498 nm, and almost complete absorption of red down to 640nm in blue and green stones; red and pink stones show lines at 458 and 451nm as well as a broad band in the green spectrum |
- Gemological Institute of America, GIA Gem Reference Guide 1995, ISBN 0-87311-019-6
- Mindat tourmaline group Accessed September 12, 2005. This website details specifically and clearly how the complicated chemical formula is structured.
විකිපීඩියා, විකි, විශ්වකෝෂය, පොත, පුස්තකාලය, ලිපිය, කියවීම, නොමිලේ බාගත කිරීම, තෝරමල්ලි පිළිබඳ තොරතුරු, තෝරමල්ලි යනු කුමක්ද? තෝරමල්ලි යනු කුමක් දර්ශනය කරන්නේ?