Chatham's Lab-Created Gemstones & Diamonds

by Kristin Coffin August 16, 2017

Chatham's Lab-Created Gemstones & Diamonds

I've been using Chatham's lab-created (also referred to as "cultured" or "lab-grown") gemstones for many years and am absolutely smitten with their sapphires. Recently, I started offering their lab-grown diamonds too! (You can read more about lab-grown diamonds in this blog post I wrote.) Not only are Chatham's gemstones gorgeous and budget-friendly, but they are the true ethical and conflict-free alternative to a mined gemstone. 

The Chatham company was started in a garage in California by Carrol Chatham over 85 years ago. Carrol was the first in the world to ever grow an emerald crystal in a laboratory. In the following decades, he perfected the growing process of other gemstones such as rubies, blue sapphires, and alexandrite. After Carrol’s passing in 1983, Carrol’s son, Tom inherited Chatham Company and Carrol’s passion for innovation. Tom ultimately fulfilled Carrol's most ambitious dream: To grow a lab grown diamond identical to those mined from the earth. 85 years later, Chatham is still the pioneer and a leader in the lab-created gemstone industry.

Carrol Chatham, founder of Chatham Gems, in his lab in 1948     First Rough Emerald Crystal Ever Grown 
(images courtesy of Chatham)

Recreating the a Lab:

Chatham built a chamber in their laboratory that recreates the intense heat and pressure required for the gemstones to grow naturally in the earth. All of the properties of the lab-created gemstones are exactly the same as natural gemstones mined from the earth, including their molecular makeup and their optical properties. Lab-created are every bit as “real” as a gemstone mined from the earth. The only difference is these gemstones are grown in Chatham’s laboratory in a controlled environment.                 

Growing a Gemstone:

In Chatham’s laboratory, the process starts with a “seed” of mined gemstone. Minerals and chemicals are then introduced at the right temperature and pressure to allow the gemstone to grow naturally over time into a jewelry-grade rough crystal. 

Once the rough crystal is grown, Chatham master gemstone cutters then orient the crystal to cut gemstones to perfect proportions, often times sacrificing up to 80% of the rough in order to achieve the perfect cut.

Rough Chatham Lab Grown Blue Sapphire

Chatham's Commitment to Purity: 

Did you know that over 95% of mined sapphires are actually treated (usually via extreme heating, but sometimes irradiation or filling as well)? Treatments are a way to greatly enhance a sapphires's color and improve its clarity. Even though the vast majority of mined sapphires undergo treatments, many are falsely labeled as "natural" by suppliers and jewelers. (By definition, a "natural" gemstone means it must be free of any treatments.) Since natural sapphires fetch a huge premium, bogus claims of "natural" sapphires have flooded the market. The fact that most mined sapphires are treated flies under the radar, and this is all too common in the industry.

On the other hand, Chatham expertly controls their laboratory environment so that the crystals grow perfectly and never require any sort of heat/irradiation/filling treatments to enhance their color or clarity. They just grow that perfectly. The overall clarity and color of gems grown by Chatham is far superior to nearly all mined sapphires. Not to mention their master stone cutters produce cuts better than the vast majority of sapphires (both mined and grown) on the market! 

Want to know more about lab-grown diamonds? Read my other blog post for an in-depth look at created diamonds. 

Kristin Coffin
Kristin Coffin