Heb. nophek (Ex. 28:18; 39:11); i.e., the “glowing stone”, probably the carbuncle, a precious stone in the breastplate of the high priest. It is mentioned (Rev. 21:19) as one of the foundations of the New Jerusalem. The name given to this stone in the New Testament Greek is smaragdos, which means “live coal.”
Emerald
2 verses
Ezekiel
Ezekiel 27:16
Syria was thy merchant by reason of the multitude of the wares of thy making: they occupied in thy fairs with emeralds, purple, and broidered work, and fine linen, and coral, and agate.
Revelation
Revelation 21:19
And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald;
From Easton's Bible Dictionary
Matthew George Easton, 1897