We comparatively studied the H2O/D2O isotope effect of lanthanide sulfate crystallohydrates on photo-,
radio-, and triboluminescence and lifetimes of the excited Ln3+ ions. Replacing H2O by D2O leads to an
increase in the luminescence intensity whereas this process does not affect the maxima positions in
photo-, radio-, and triboluminescence spectra. This isotope effect agrees with the known concepts of
changes in luminescence quantum yields of the Ln3+ ions being the main emitters. The bands of OH
and OD radicals arise in triboluminescence spectra of lanthanide sulfate crystallohydrates (with H2O or
D2O) registered in argon atmosphere in UV region. This supports the proposition that water destruction
occurs at the degradation of the crystallohydrates.