Overview
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.”
Birthstones & Anniversaries
As the gem of spring, emerald is the perfect choice as the birthstone for the month of May. It’s also the gem of the twentieth and thirty-fifth wedding anniversaries.
2.97 Billion Years
Age of the oldest emeralds, from South Africa.
Cleopatra
Pharaoh known for her passion for emeralds.
$6,578,500
2011 sales price for Elizabeth Taylor’s emerald pendant - that's $280,000 per carat.
Facts
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Mineral:
Beryl
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Chemistry:
Be3Al2Si6O18
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Color:
Vibrant green
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Refractive Index:
1.577 to 1.583
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Birefringence:
0.005 to 0.009
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Specific Gravity:
2.72
- Mohs Hardness: 7.5 to 8
Treatments
There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.
Learn MoreSynthetics
Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.
Learn MoreImitations
Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.
Learn MoreWhy We Love This Gemstone
Three-Phase Inclusions
Three-phase inclusions in Colombian emeralds contain tiny crystals of rock salt, liquid, and a bubble of gas.
Hexagonal Crystals
The best emerald crystals are gorgeous flat-topped green hexagonal columns that are as beautiful as faceted stones.
Ancient Egypt
The first known emerald mines were in Egypt. It is believed that these mines were worked as early as 3500BC.
Quality Factors
Emerald has been the standard for green colored stones for millennia.
Color
The most desirable emerald colors are bluish green to pure green, with vivid color saturation.
Clarity
In Emerald expect to see inclusions that dealers like to call an internal “jardin,” or garden.
Cut
Due to the crystal shape emeralds are commonly cut as rectangular step cuts called emerald cuts.
Carat Weight
Because its density is lower, a one-carat emerald will appear larger in size than a one-carat diamond.
Emerald Quality Factors: The Comprehensive Guide
Research
Explore sources, gemological research, and the role of gems in history.
A New Discovery of Emeralds from Ethiopia
Nathan Renfro, Ziyin Sun, Michael Nemeth, Wim Vertriest, Victoria Raynaud, and Vararut Weeramonkhonlert , May 8, 2017 Read ArticleIn Rainier’s Footsteps: Journey to the Chivor Emerald Mine
Robert Weldon, Jose Guillermo Ortiz, and Terri Ottaway , Aug 3, 2016 Read ArticleRecommended Reading
Emerald: The Most Valuable Beryl; The Most Precious Gemstone
Christa Behmenburg, et al.
The Ruby, Sapphire and Emerald Buying Guide: How to Identify, Evaluate and Select These Gems
Renée Newman