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Emerald
Emerald [EBD]
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 [NAVE]
EMERALD, a precious stone. Color of the rainbow, Rev. 4:3.Merchandise of, in Tyre, Ezek. 27:16; 28:13.
Set in the breastplate, Ex. 28:18.
Symbolical
In the foundation of the holy city, Rev. 21:19.
EMERALD [SMITH]
a precious stone of a rich green color, upon which its value chiefly depends. This gem was the first in the second row on the breastplate of the high priest. (Exodus 28:18; 39:11) It was imported to Tyre from Syria, (Ezekiel 27:16) was used as a seal or signet, Ecclus. 32:6, as an ornament of clothing and bedding, (Ezekiel 28:13; Judges 10:21) and is spoken of as one of the foundations of Jerusalem. (Revelation 21:19) Tob. 13:16. The rainbow around the throne is compared to emerald in (Revelation 4:3)Also see definition of "Emerald" in Word Study