Exodus 28:11

28:11 You are to engrave the two stones with the names of the sons of Israel with the work of an engraver in stone, like the engravings of a seal; you are to have them set in gold filigree settings.

Exodus 31:18

31:18 He gave Moses two tablets of testimony when he had finished speaking with him on Mount Sinai, tablets of stone written by the finger of God.