Formula: Nb2(O,OH)6 . nH2O
Reflected/transmitted colour:
Pleochroism:
Optical isotropy/anisotropy: Isotropic
Optical sign: n = 1.93-1.99
Refractive indices:
Bireflectance/Birefringence δ:
2V angle:
Dispersion:
Optical orientation:
Optical axial plane:
| Back to Alphabetical list | Colour photos | Physical, chemical and crystallographic description | SEM images | TEM images | vibrational spectra description | IR spectra | Raman spectra | N-IR spectra | F-IR spectra | IES spectra |