the emerald or green gem so called Derivation: of uncertain derivation;
KJV Usage: emerald.
TBESG:
σμάραγδος
emerald
G:N-M
σμάραγδος, -ου, ἡ (and in late writers also ὁ), [in LXX: Exo.28:9 (שֹׁהַם) Refs Exo.36:17 (Exo.39:10) (בָּרֶקֶת), Eze.28:13 (יַהֲלֹם), etc. ;] emerald or other trans parent green stone (LS, see word; DB, iv, 620; Swete, Ap., 67, 288): Rev.21:19.† (AS)
Thayer:
1) a transparent precious stone noted especially for its light green colour
σμάραγδος
smaragdos
smar'-ag-dos
Of uncertain derivation; the emerald or green gem so called