'Pearl' in the Bible

and having found one pearl of great price, he went and sold all that he had, and bought it.

saying, Woe, woe, the great city, she that was arrayed in fine linen and purple and scarlet, and decked with gold and precious stone and pearl!

And the twelve gates were twelve pearls; each one of the several gates was of one pearl: and the street of the city was pure gold, as it were transparent glass.