Emerald is the bluish green to green variety of beryl, a mineral species that includes aquamarine.
Gem experts differ on the degree of green that makes one stone an emerald and another stone a less-expensive green beryl. Most gemologists, gemological laboratories, and colored stone dealers call a stone green beryl when its color is “too light” for it to be classified as emerald. Even among that group, however, there’s a difference of opinion about what’s considered “too light.”
|Anniversary||20th and 35th wedding anniversaries|
|Refractive Index||1.577 to 1.583|
|Birefringence||0.005 to 0.009|
|Mohs Hardness||7.5 to 8|