Whiteite

Formula: Ca(Fe,Mn)Mg2Al2(PO4)4(OH)2.8H2O

Reflected/transmitted colour:

Pleochroism:

Optical isotropy/anisotropy: Biaxial

Optical sign: +

Refractive indices: α = 1.580, β = 1.585, γ = 1.590 (CaFeMg), α = 1.580, β = 1.584, γ = 1.591 (CaMnMg), α = 1.580, β = 1.584-1.585, γ = 1.590-1.591 (MnFeMg)

Bireflectance/Birefringence δ: 0.010 (CaFeMg), 0.011 (CaMnMg), 0.010-0.011 (MnFeMg)

2V angle: 88° (calculated), 40-50° (measured) (CaFeMg), 76° (calculated), 74-81° (measured) (CaMnMg)

Dispersion:

Optical orientation:

Optical axial plane:

 

Back to Alphabetical list Colour photos: whiteite-(CaFeMg), whiteite-(CaMnMg), whiteite-(MnFeMg) Physical, chemical and crystallographic description SEM images TEM images vibrational spectra description IR spectra Raman spectra N-IR spectra F-IR spectra IES spectra