Optical Spectra of Apophyllite, KCa₄Si₈O₂₀(OH,F)·8H₂O

• Platonov AN, Tarashchan AN (1973) Optical spectroscopy of vanadium in natural minerals. III. Absorption spectra of vanadium(4+) and vanadium(3+) complexes. Konstitutsiya i Svoistva Mineralov 7, 75-81. In Russian

• Rossman GR (1974) Optical Spectroscopy of Green Vanadium Apophyllite from Poona, lndia. American Mineralogist 59, 621-622.
  

• Platonov AN, Krasil'shchikova OA, Tarashchan AN (1975) Optical absorption of rare earth ions in minerals. Konstitutsiya i Svoistva Mineralov, 9, 58-64.  In Russian