Answer: zirconia

AnswerCrossword Clue
ZIRCONIACubic stone?
ZIRCONIACubic ... (synthetic gemstone)
ZIRCONIACompound used in abrasives
ZIRCONIACubic ... (gem)
ZIRCONIAMetal oxide in dental crowns
zirconiawhite, heavy, amorphous, odorless and tasteless, infusible, water-insoluble powder, ZrO2, used chiefly as a pigment for paints, an abrasive, and in the manufacture of refractory crucibles
zirconiaoxide of zirconium