The visible quantum cutting via cross-relaxation between Tb3+ ions in Na3Gd0.9-xYxSi3O9:0.1Tb(3+) phosphors are identified for the first time. It has also been found that with the increase of the ratio of Gd3+/Y3+, the quantum cutting efficiency increases, which indicates the Gd3+ plays an important intermediate role in energy transfer to convert vacuum ultraviolet light to visible light and reinforces the cross relaxation efficiency during the quantum cutting process. In addition, the energy transfer process from Gd3+ to Tb3+ is also investigated and discussed in terms of luminescence spectra. (C) 2013 Elsevier Ltd. All rights reserved.