Emma Scaramozzino - March 9, 2021
Everything You Need to Know About: Emeralds
The second installment of our Everything You Need To Know Series. This week we'll be covering emeralds; where they come from, how to buy one, and more.
For over 500 years, Colombia has been a hub for the finest quality emeralds. Each emerald varies in color depending on which of the three main mines they came from. Muzo emeralds are known to have darker tones, stones from Chivor tend to have a lighter tone along with a blue-green tint, and Coscuez is known for their slightly yellow tinted emeralds.
Other important sources of emeralds include African mines in Zambia and Ndola Rural Restricted Area, which are known for producing emeralds that are bluish green and darker in tone. Pakistan and Afghanistan are also important producers.
Similarly to sapphires, emeralds are graded differently depending on the size one wants.
When looking for emeralds for everyday jewelry, typically below one carat, the color scale ranges from AAA - B. Stones are labeled with these letters based on rarity. For example, an AAA stone (fine quality) accounts for 2% of all natural gemstones, AA accounts for 10%, A for 20%, and B, 50% (a more commercial grade stone).
When looking for an emerald (typically over one carat) that is fine quality, you would ask your jeweler to find you a "Gem". According to Saul Nhaissi, @saulnice the gemologist on Instagram, "Gem is a term used to describe the best quality in gemstones, for any size above one carat. Essentially, the term gem emphasizes that the client needs to see the very best options within the carat range they're looking in". In the case of emeralds, the most desirable colors are bluish green to pure green, with vivid color saturation and tone that’s not too dark.
Unlike diamonds and other gemstones, visible inclusions are common, and therefore more accepted in emeralds. Gemologist Saul Nhaissi points out that since inclusions are frequently found in emeralds, the placement of the inclusions or fractures in the stone are the biggest factor that determines how valuable it is. If these imperfections are placed under a facet where it is less visible, can easily be covered by a prong, or doesn't effect how light interacts with the stone, it is more valuable.
Generally, there are three types of emeralds in terms of grading: Type 1: Very Slightly Included, Type 2: Slightly Included, Type 3: Included. However, eye and loupe-clean emeralds do exist, they are quite difficult to find and very expensive.
*Fun Fact: Emeralds are sometimes called jardin (french for garden) because of their mossy, garden-like appearance).*
Source: @saulnice on Instagram
Luster is the way light interacts with the surface of a stone. Also known as crystal or the "life" in a stone, this seemingly slight difference between stones can raise the price of a gem significantly. You can see this difference in the above two stones; the right stone is "more lively" compared to the stone on the left. This interaction between the stone and light is noted in the transparency portion of the certificate. When a stone is transparent, it has good luster. When it is translucent or opaque, it lacks luster.
Source: Diamond Advisor
The density of a stone is what determines its carat weight. Because density varies between stones, carat weight differs even if two stones have the same dimensions. For example, if a ruby is 9x7mm it weighs in at around 2.96 carats. However, a 9x7mm emerald weighs in at about 2 carats. Emeralds are less dense than most precious gems.
Since emeralds are known to have visible inclusions, it's quite common to use oil and resin treatments as a way to improve their clarity. Palm oil, also known as Palma, is the most commonly used oil to enhance an emerald's clarity. This further improves its overall quality and grade.
When purchasing a large emerald, especially as the center stone of an engagement ring, you may receive a certificate along with it. Certifications typically come from notable labs such as GIA, Lotus, AIGS, CDC, and IGI.
It is also important to note that on emerald certificates, color is not always listed. Some labs will state that a stone is imperial or vivid green, though some don’t list it because color is relative. For example, one lab's perception of vivid green may be different than another. The most important thing to look at is the variety on a certificate - this will differentiate if a stone is an emerald or just a beryl (the species in which an emerald stems from).
Source: Shahla Karimi
Lab Grown Emeralds
Just like diamonds, lab grown emeralds are 100% atomically the same as natural emeralds. However, the color of cultivated emeralds is still being perfected. The prettiest variety we have seen thus far is a vivid green with a lot of blue and a more commercial deep green. The color difference may be worth it though; lab grown emeralds are 25 - 50% the price of natural, depending on the carat size.
Source: Shahla Karimi
Emeralds are the softest of the big four (diamonds, emeralds, rubies, and sapphires), scoring a 7.5 out of 10 on the Mohs scale. The Mohs scale measures gem and mineral hardness, and the numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. Since the majority of natural emeralds contain fractures, and are on the softer side, it’s risky to clean them in an ultrasonic or with steam. The best way to clean them is by gently scrubbing with warm, soapy water.
Birthstone Meanings + Healing Properties
Emeralds are known to be a "royal" stone in many ancient societies. Pharaohs in particular are widely-known to have this belief, as they often incorporated them in pieces worn by royals. The same was believed by ancient societies in South America; the Crown of the Andes is a perfect example of this.
The stones were often worn by royals because they were known to hold magical powers. By placing it under the tongue, one could see into the future. Some believed it made one an eloquent speaker and exposed lovers who made false promises.
Today, emeralds are believed to have therapeutic properties, and science has proven this to be true; the color green relieves stress and eye strain.
The Chalk Emerald (Top) weighs in at 37.8 carats and has particularly outstanding clarity and color. Originally purchased by Mr. and Mrs. O. Roy Chalk, it now is on display in the Museum of Natural History in NYC.
Elizabeth Taylor's Emerald (Bottom Left) was purchased as a gift for her by then boyfriend Richard Burton. It weighs in at 23.46 carats.
The Rockefeller Emerald weighs in at 18.04 carats, and was purchased by John D. Rockefeller Jr. for his wife, Abby Aldridge Rockefeller, who wore it for years as part of a brooch that was designed by Van Cleef & Arpels. After her death, the brooch was broken down and the stones were distributed to her children.