Although crystal oscillators still most commonly use quartz crystals, devices using other materials are becoming more common, such as ceramic resonators.
alThouGh cRYstal oSCillatoRs STIll MosT cOmMonLy use QuaRtz CryStalS, deviCEs USIng otHeR mAteriAls arE BEComing MORe common, suCH as cEramIc resOnAtoRs.