Exodus 39:10

And they set in it four rows of stones: the first row was a sardius, a topaz, and a carbuncle: this was the first row.

Cross-reference

Exodus 28:17 gives the original command for the first row of stones—ruby, topaz, emerald—exactly as executed here.

Exodus 28:21 explains that the twelve stones represent the tribes of Israel, each engraved with a name, giving meaning to this mounting.