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How to Choose High Quality Emeralds

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Emeralds have been among the most prized gemstones on earth for over four millennia. They have famously adorned Queen Cleopatra, Catherine the Great, and modern celebrities such as Angelina Jolie. Culturally they are valued as auspicious talismans for many ailments, from safe childbirth to soothsaying. They are most written about as being a remedy for strained or failing eyes, as William Shakespeare wrote in “A Lover's Complaint” in 1609 “The deepe greene Emerald in whose fresh regard, weak sights their sickly radiance do amend.”

Humanity has been captivated by the emerald’s rare and beguiling shades of green - a magical, almost indescribable experience that has been a subject of poetry throughout the ages, going back to the ancient Roman time of Pliny the Elder (died 79 CE) “Indeed there is no stone, the color of which is more delightful to the eye, for whereas the sight fixes itself with avidity upon the green grass and the foliage of the trees, we have all the more pleasure in looking upon the smaragdus (emerald), there being no green in existence of a more intense color than this.”

The magnetism of emeralds is clear, and I have been fortunate to learn how they are mined. Having visited the Chivor emerald mines in Colombia myself, I have seen the presence of ancient mines, as well as an artisanal one.

There are also more mechanized modern mines in operation, and the precedence for mining is generally well established. This transparency is the foundation for an ethical provenance. Emeralds are found in the depths of the Andes mountains, and tunnels lay bare the emerald material. Water, dynamite and manual labor are used to flush out the rock.

Does it Matter Where My Emerald Comes From?

Emeralds are mined the world over, most commonly in Colombia, Zambia, Zimbabwe, and Brazil, though of interest there are also small emeralds pockets in North America.

Colombian emeralds comprise up to 90% of the world’s emerald market. And most of these come from three Colombian mining areas in particular: Muzo, Chivor, and Coscuez, all in the Andes Mountains. 

The history of the Colombian emerald is a bit of a tortured one. The indigenous Muzo people of Colombia mined emeralds as far back as 300 AD, until Spanish conquistadors took control and forced them into slave labor in the 15th and 16th centuries. Colonization decimated the native populations, and emerald production all but ceased until Colombia gained its independence in 1819.

After independence, when government and private companies slowly resumed mining, labor conditions were brutal and extraction methods were dangerous and destructive, all ruled by corrupt systems. In the last 20 or so years, this has evolved considerably when the ownership of the mines changed (a fascinating history in and of itself). 

Why We Choose to Source Colombian Emeralds

The mining of any gem is a costly and inherently unsustainable proposition. I appreciate Colombian emeralds as the system and protocols for mining emeralds is done in both a modern and more artisanal or traditional way, each with their own advantages.

Shield Colombian emerald fancy yellow diamond pendantThe government regulates that miners work in safe and humane conditions that exceed national labor standards, often receiving health insurance and two times the country’s minimum wage. As tunnels are mostly established, they use less invasive mining practices without toxic chemicals, and it has been reported to me  that the government works to restore mining regions through community-led environmental efforts. 

For the first time in hundreds of years, consumers have the opportunity to own emeralds of superior quality and improved ethics.

How to Assess the Quality of an Emerald

It is important to understand the quality of an emerald. Like all gemstones, emeralds are graded on the 4 Cs: Color, Clarity, Cut, and Carat. But we assess these characteristics in emeralds somewhat differently than, say, diamonds or rubies. 

  • Color

Emeralds are arguably about color more than anything else. A vivid green to bluish green is most desirable. Look for a tone that is not too dark, with evenly distributed color and rich saturation. However, there is material that is light and lustrous which captivates my attention as well- ultimately this is subjective to the client and our individual personal tastes. Do not be afraid to trust your instincts and desires. 

  • Clarity

Clarity refers to an emerald’s brilliance, or how well it reflects light. Ideal emerald brilliance is satiny and soft, relatively clear, appearing to glow. Clarity also refers to the presence of inclusions, or visible particles or fractures inside the gemstone. It’s exceedingly rare for an emerald to have zero inclusions. Minor visible inclusions are actually accepted in high-quality emeralds, as long as they don’t reduce clarity.

The correct inclusions, which give the gem character without threatening integrity can add interest and value. Gota de aceite or “drop of oil” is used to describe a very rare and exceptionally valuable optical phenomenon that presents as whiskey in water, a butterfly's wing, or honey. Emerald inclusions can be described as “jardin,” French for garden, as the inclusions can have a mossy or garden like appearance.

Most emeralds are treated with traditional cedar oil or a synthetic oil. The oil will fill some inclusions and improve the clarity of an emerald. Treatment with oil is reversible. Oil is generally stable, but if oil leaks out of the stone over time, or the stone is exposed to a solvent such as alcohol or acetone, the stone can be retreated.

No treatment for an emerald is generally most desirable, and this is designated by a notable laboratory certification. Such emeralds are quite rare, and a small amount of treatment, designated “insignificant” or “minor” oil, or even ‘moderate’ is acceptable if the specimen is otherwise desirable. Emerald specimens with significant oil treatment or treatment with permanent glues or resins are not sourced by Thesis. 

  • Cut

Emeralds are challenging to cut because they are more brittle than other gems and commonly have fissures. Plus, the cut greatly impacts tone and saturation. Look for an attractive cut that maximizes the stone’s color and that appeals to you. Traditional emerald cuts, the emerald being this styles namesake, are most popular. I obtain pleasure from all cuts and styles of emeralds, as well as unfaceted cabochon cuts. 

  • Carat

Higher carat weight doesn’t automatically equal more value. Of course, this is often the case, but only when combined with high-quality color, clarity, and cut. Rather than focusing on an emerald’s carat weight, look for gorgeous color and brilliance, and a cut and size that displays beautifully in its setting. 


Emeralds Forever

Choose an heirloom-quality emerald from a prized source in the world. Whether you fall in love with one of our existing designs, or design your own, Thesis offers full transparency from the mines to the finished piece.

Reach out today to learn how you can invest in an emerald you will be proud to wear and pass down for generations to come.