Formula: (Na,Ca,K)6-8(Al6Si6O24)(CO3,SO4,Cl,OH)1-2.1-5H2O
Reflected/transmitted colour: colourless
Pleochroism: -
Optical isotropy/anisotropy: uniaxial
Optical sign: -
Refractive indices: ε = 1.488-1.502, w = 1.490-1.528
Birefringence δ: 0.002-0.025
2V angle:
Dispersion: very weak
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 |