The name Emerald is a girl's name of Persian origin meaning "green". Emerald and is often added to lists like Color Names for Babies and discussed in our forums with posts like "Quintuplet Game-GIRLS".
From the experts:
Emerald is the intriguing color and jewel name of the deep green stone treasured as far back as ancient Egypt--it's supposed to open one's heart to wisdom and to love and be good for strengthening relationships-- which could make for an interesting, unusual name, particularly with the popularity of so many Em-starting names.
Emerald is the birthstone of May, making it extra appropriate for a girl born in that month. Some pleasant associations: the Emerald Isle and the Emerald City.
Esmeralda is the more exotic Spanish version.