Fluorine-rich miserite glass compositions with variable K2O to CaO ratios, K-x(Ca,Ce)(5-x),Si8O21.5F3 where x = 1, 2 or 3, have been investigated in term of crystallization path and Ce3+ substitution. For sake of comparison a second series without ceria was also prepared: K-x(Ca,Ce)(5-x),Si8O22F2. Xonotlite, tokkoite, fluorite and cristobalite were developed in all crystallized glasses; however, miserite was only identified in Ce-containing samples. Increase of K2O/CaO ratio, in Ce-free sample, enhanced the formation of tokkoite, and reduced the contents of xonotlite and fluorite. On the other hand, in Ce-containing samples, an increase of K2O/Ca ratio promotes the formation of miserite crystals. Quantitative Rietveld analyses assessed the presence of Ce3+ cations in miserite structure. The microstructure of Ce-free glass-ceramics was relatively coarse in the form of interlocked flakes and rods; however, it became unpronounced in the sample of highest K2O/Ca ratio. In Ce-containing glass-ceramics, irregular nanosized grains were spread in cryptocrystalline groundmass, whose fineness increased with increasing K2O/Ca ratio. The CTE values of the parent glasses and their glass-ceramics varied from 10.31 to 11.05 and from 7.52 to 9.84 x 10(-6) C-1 respectively with lower values for Ce-free glass-ceramics. Density and micro hardness values were also measured. (C) 2014 Elsevier B.V. All rights reserved.