Their classical culture was a varied mixture of Pannonian, Illyrian, Greek and Roman influences, mostly without proper peculiarities. Their figural art included the frequent metal decorations in the form of triangles and spirals, and large amber pearls and amber figurines. The Iapydic language before the Romans is mostly unknown: the only indications available are their toponyms and necropolis inscriptions from Roman times. These scarce onomastic indications suggest the Iapydic tongue may be correlated with other Illyrian and Pannonian tribes. During their independence, the Iapydes appear to have been completely illiterate and left no inscriptions before the Roman conquest.