Input interpretation
chromdravite (mineral) | sursassite (mineral)
Images
Images
General properties
| chromdravite | sursassite alternate names | chromium-dravite | tourmaline | (none) formula | NaMg_3(Cr, Fe^(3+))_6(BO_3)_3Si_6O_18(OH)_4 | Mn^(2+)_2Al_3(SiO_4)(Si_2O_7)(OH)_3 discovery year | 1983 | 1926
Basic properties
| chromdravite | sursassite density | 3.4 g/cm^3 | 3.256 g/cm^3 transparency | translucent | opaque | transparent | translucent birefringence | 0.056 | 0.03 luster | vitreous | resinous | silky | dull Mohs hardness | 7.25 | streak | greenish gray | yellowish brown magnetism | nonmagnetic | nonmagnetic color | greenish black | dark green | deep reddish brown | copper red molar mass | 1115 g/mol | 502.1 g/mol
Units
Mineral identifiers
| chromdravite | sursassite Strunz ID | VIII/E.19-30 | VIII/C.24-20 Dana ID | 61.3e.1.11 | 58.2.3.1 IMA number | IMA1982-055 | ICSD number | | ICSD40031
Crystallographic properties
| chromdravite | sursassite crystal system | trigonal | monoclinic crystal class | 3m | 2/m unit cell volume | 1634 Å^3 (cubic ångströms) | 418.4 Å^3 (cubic ångströms) d-spacing | 2.62 Å (ångströms) | 3.04 Å (ångströms) | 3.58 Å (ångströms) | 2.82 Å (ångströms) | 2.57 Å (ångströms) | 2.88 Å (ångströms) intensity | 100% | 75% | 75% | 100% | 70% | 70% molecules per unit cell | 3 molecules per cell | 2 molecules per cell 2V angle | | 2 π/5 radians≈72° (degrees) refractive indices | 0 | 0 | 0 | 1.779 | 1.723 | 0 | 1.736 | 0 | 0 | 0 | 0 | 0 dispersion | | r > v unit cell lengths | 16.11 Å (ångströms) | 7.27 Å (ångströms) | 7.27 Å (ångströms) | 8.7 Å (ångströms) | 5.79 Å (ångströms) | 8.78 Å (ångströms) unit cell angles | 90° (degrees) | 90° (degrees) | 120° (degrees) | 90° (degrees) | 108.9° (degrees) | 90° (degrees)
Wikipedia summary
Chromdravite
Tourmaline is a crystalline boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gemstone comes in a wide variety of colors.