Crystal growth of rare-earth boron-rich solids in RE-B-C(-N) and RE-B-Si systems from Cu and Si solutions has been studied. The grown crystals are RExB22C3-deltaNdelta (x=0.6-0.8, 0less than or equal todeltaless than or equal to1), RExB28.5C4 (RE=Y, Ho, Er, Tm, Lu), REB25C5 (RE=Y, Tb) and RExB12Sisimilar to3 (x=0.65-0.7, RE=Y,Gd-Lu). The first two phases are built with interconnected boron icosahedra and octahedra, which are regarded as homologous phases of B4C. REB25C5 is a superstructure of YAlB14-type YB25C and RExB12Sisimilar to3 is a new structure type. The crystal growth conditions and crystallography are described in this paper. (C) 2004 Elsevier B.V. All rights reserved.