Spectroscopy of compounds from the family of rare-earth orthoborates

This paper is devoted to the rare-earth borates described by the general formula RM3(BO3)4, M = Al, Fe, and Cr, that have non-centrosymmetric trigonal structure of the natural mineral huntite. It give a brief review of a spectroscopic research on YbAl3(BO3)4 (YbAB), on a large group of magnetic iron borates, and on NdCr3(BO3)4.