Last updateTue, 11 Feb 2020 10pm

The Story Behind the Stone: A look inside Emeralds

Emeralds are so prone to natural inclusions, or jardin as experts call them, that a flawless green emerald is looked upon with suspicion. While the branch-like fractures are common with this verdant beryl variety, some of them could have been avoided.

Different gemstones have their individual method of recovery. Some are harvested by alluvial methods - and that means sorting through riverbed rocks for the sparkly bits. Open pit or tunnel mining define other methods of hunting the glorious rocks that people covet.

Emerald mining camp deep in the Amazon with emerald miner Andy Rendle. Courtesy of Andy Rendle.
But when it comes to emerald, it’s all D & B, baby; drill and blast. Some alluvial emerald mining happens, but most emerald harvesting occurs by digging underground through hard pegmatite veins with drilling and blasting. The concussive waves from these explosions may actually increase fractures to delicate emerald crystals.

Expert Colombian emerald miner, Andy Rendle and his research and development group at Rio Verde/Emerald Stone have explored solutions for combating this dilemma; aimed at retrieving cleaner more valuable crystal rough.  Rendle’s team has devised proprietary machines that extract crystals in a manner less invasive while protecting them from the extreme concussive fractures they are prone to under traditional drill and blast, or D & B methods. Less destruction to the earth ensues and their process reintroduces the sterile material back into the earth to fill up the excavation. So the effect on the mountainous areas is negligible.

It’s efforts like this at the mine site that produce jaw dropping cut emeralds on the red carpet; those fabulously clean gemstones that look nothing like the ordinary colored stones in franchise mall jewelry kiosks. Reverential awe is paid to emeralds that survive their recovery in tact with few of these telltale ruptures. And an enormous premium is paid for super clean emeralds of any size, the larger the rarer of course.

Catherine the Great’s emerald and diamond brooch, set with a Colombian emerald of over 60 carats. Courtesy of Christie’s New York.
Recently, Angelina Jolie took red carpet gawkers off guard with her colossal tear drop pendant earrings at an awards ceremony. Green, yes. Jumbo, you bet. But emeralds? Absolutely. We don’t know what the condition of these Fred Leighton wonders was; nearly flawless or enhanced? But they provide us with another glimpse into why they cause explosions in the hearts of jewelry fans everywhere.

Award winning trade journalist and gemologist Diana Jarrett is also a Registered Master Valuer Appraiser and a member of the National Association of Jewelry Appraisers (NAJA). She’s a popular speaker at conferences and trade shows. Jarrett writes for trade and consumer publications, various online outlets, and for sightholders and other industry leaders.. Contact her at This email address is being protected from spambots. You need JavaScript enabled to view it., visit her website, www.dianajarrett.com, and/or follow her on FaceBook and Twitter (Loupey).