Word Origin & History
emeraldc.1300, from O.Fr. emeraude, from M.L. esmaraldus, from L. smaragdus, from Gk. smaragdos "green gem," from Sem. baraq "shine" (cf. Heb. bareqeth "emerald," Arabic barq "lightning"). Skt. maragdam "emerald" is from the same source, as is Pers. zumurrud, whence Turk. zümrüd, source of Rus. izumrud
"emerald."
"In early examples the word, like most other names of precious stones, is of vague meaning; the mediæval references to the stone are often based upon the descriptions given by classical writers of the smaragdus, the identity of which with our emerald is doubtful." [OED]