Answer: zircon

AnswerCrossword Clue
ZIRCONDecember birthstone
ZIRCONClear gemstone
ZIRCONDecember stone
ZIRCONTransparent gemstone
ZIRCONDiamond substitute
ZIRCONGem.
ZIRCONGem
ZIRCONMatura diamond
ZIRCONMatura diamond, actually
ZIRCONModern December birthstone
zirconmineral that is used as a gem when transparent