Formula: (Y,Ca,Fe,Th)(Ti,Nb)2(O,OH)6
Reflected/transmitted colour:
Pleochroism:
Optical isotropy/anisotropy: biaxial to isotropic when metamict
Optical sign: +
Refractive indices: α = 2.19-2.28, β = 2.21-2.30, γ = 2.34-2.50
Birefringence δ: 0.22-0.31
2V angle: 70-80°
Dispersion: r > v, strong
Optical orientation: α = a, β = c, γ = b
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 |