Zoisite Visible Spectra (400 - 1000 nm)

The blue variety, tanzanite, is colored by vanadium. It is highly pleochroic before it is heat-treated for the commercial gem market. Pink zoisite contains Mn3+. Green varieties contain Fe3+.


  Images of the zoisite absorption spectrum

      Tanzanite


    Pink Zoisite


    Green Zoisite


    Pale Yellow Zoisite

Link to references about the spectra of zoisite


Faye GH and Nickel EH (1971) On the pleochroism of vanadium-bearing zoisite from Tanzania. Canadian Mineralogist  p812.

Langer K, Tillmanns E, Kersten M, Almen H, Arni RK (2002) The crystal chemistry of Mn3+ in the clino- and orthozoisite structure types, Ca2M33+[OH|O|SiO4|Si2O7]: A structural and spectroscopic study of some natural piemontites and “thulites” and their synthetic equivalents. Z Kristallogr 217:563-580


last  updated: 20-Dec-2014