Lanthanide orthoborates of composition LnBO(3) (Ln = Tb, La, Pr, Nd, Sm, Eu, Gd, Dy, Y) and LaBO3:Gd, Tb, Eu have been prepared by metathesis reaction. This method provides a convenient route for the synthesis of orthoborates and its solid solutions at low temperatures. Powder X-ray diffraction and FT-IR spectroscopy were used to characterize these borates. Rare earth borates, (LnBO(3)) are isomorphous with different forms of CaCO3 depending on the radius of rare earth ion. LaBO3, LaBO3:Gd, Tb, Eu, PrBO3, NdBO3 crystallized in aragonite structure, SmBO3 crystallized in H-form and TbBO3, EuBO3, GdBO3, DyBO3, YBO3 crystallized in vaterite structure. The structural analysis of TbBO3 was carried out. The morphology of these borates was obtained from Scanning electron microscopy. Spin-Hamiltonian parameters for Gd3+ are deduced from room temperature electron spin resonance spectrum of LaBO3:Gd. The luminescence of LaBO3:Tb, Eu gave characteristics peaks corresponding to Tb3+, Eu3+ respectively. (C) 2011 Elsevier Ltd. All rights reserved.