Inventions relates to scintillation substances and they may be utilized in nuclear physics, medicine and oil industry for recording and measurements of X-ray, gamma-ray and alpha-ray, nondestructive testing of solid states structure, three-dimensional positron-emission tomography and X-ray tomography and fluorography. Substances based on silicate comprising lutetium and cerium characterized in that compositions of substances are represented by chemical formulae CexLu2+2y−xSi1−yO5+y, CexLiq+pLu2−p+2−y−x−zAzSi1−yO5+y−p, CexLiq+pLu9.33−x−p−z□0.67AzSi6O26−p, where A is at least one element selected from group consisting of Gd, Sc, Y, La, Eu, Tb, x is value between 1×10−4 f.units and 0.02 f.units., y is value between 0.024 f.units and 0.09 f.units, z is value does not exceeding 0.05 f.units, q is value does not exceeding 0.2 f.units, p is value does not exceeding 0.05 f.units. Achievable technical result is the scintillating substance having high density, high light yield, low afterglow, and low percentage loss during fabrication of scintillating elements.