May is Emerald

If you have a May birthday, you have been blessed with an emerald as your birthstone.  It is a deep rich and vivid green color and it is believed to bring love into your life.  Historians estimate that Egyptians mined emeralds as early as 3500BC, and an emerald has been noted as one of the precious stones in the Old Testament.

Emeralds are classified within the beryl family of gemstones.  It is a cousin, so to speak, of aquamarine.  The most desirable emerald color is a strongly saturated bluish-green to green with  a medium to medium-dark tone.  If the color is not deep enough or green enough, it will be classified as a green beryl. 

All emeralds have inclusions that are visible to the naked eye.  High quality emeralds that have a few eye-visible inclusions with no negative effect on transparency of the stone are acceptable.  Sometimes, these emeralds are treated with colorless oil or clear resin to improve the emerald’s color and clarity.  Low quality emeralds have too many inclusions and fractures which affect the gem’s clarity and dramatically reduces their value.

Emeralds are a relatively fragile stone because of the inclusions and fractures that occurred during crystal growth formation.  It is however 7.5-8 on the Mohs scale, which is moderate on the hardness scale.  Cutters look deep into the stone before cutting to minimize the effect of fractures on the finished stone.  One solution was “the emerald cut” which retained as much of the stone’s material when cutting & shaping as possible...a rectangle with beveled corners.

Emeralds are mined primarily in Colombia, Zambia, Brazil and Zimbabwe.  Colombian emeralds tend to be greener and considered the world’s finest.  South African emeralds tend to have a bluer component to the green color.

Lab-grown emeralds have fewer inclusions and a higher clarity than natural emeralds.  Like with natural diamonds and lab-grown diamonds, lab-grown emeralds have different characteristics and inclusions as compared to their natural counterparts.  A jeweler can tell the difference using magnification.

The best way to clean an emerald is to use warm soapy water with a baby’s toothbrush. Never use an ultrasonic machine!