The Anderson-Evans cluster, {CrMo6O24}n-, exhibits ruby-like red emission. During our attempts to engineer new photoluminescent crystals using chromium molybdate as a molecular building block, we isolated four new rare-earth based chromium molybdates: [Gd(H 2O)7{CrMo6(OH)6O18}] ·4H2O, 1, (4-pycH)[Gd(H2O)4{CrMo 6(OH)6O18}(4-pycH)]·5H2O, 3, and (4-pycH)2[Ln(H2O)6{CrMo6(OH) 6O18}]·2H2O, (Ln = Tb, 4 and Sm, 5; H4-pyc = 4-pyridine carboxylic acid and 4-pycH = 4-pyridinium carboxylate). All are nonmolecular solids characterized by extended 1-D or 2-D interactions between rare-earth ions and the chromium molybdate cluster. All solids showed intense room-temperature Cr3+ related red emission and also exhibited weak antiferromagnetism at low temperatures. This journal is © the Partner Organisations 2014.