Formula: (Mn,Fe)SiO3
Reflected/transmitted colour: colourless to faint lilac
Pleochroism: -
Optical isotropy/anisotropy: biaxial
Optical sign: +
Refractive indices: α = 1.728-1.748, β = 1.730-1.752, γ = 1.746-1.758
Birefringence δ: 0.016-0.019
2Vγ angle: 37-45°
Dispersion: r > v, moderate
Optical orientation:
Optical axial plane: approximately ┴ (1-10)
| 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 |