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The Best Gems On Earth

Chatham grows gorgeous gem crystals, cuts them precisely to sparkle with brilliance, and crafts unique jewelry designs to showcase their beauty. We are one of the few vertically integrated brands in the jewelry industry, which allows us to offer you exceptional quality and value. That’s why more people choose Chatham than any other lab-grown gem.

Chatham-created gems are in the collection of the Smithsonian Institution and the collection of the Gemological Institute of America. We’re proud of our rich history but even more proud that our tradition of innovation continues today.

Original sketch
1 Original sketchclick to enlarge
rough crystal
2 rough crystal
cut stone
3 cut stone
finished necklace
4 finished necklace
a rough gem

why chatham?

We grow the best gems on earth. And we don’t think you should settle for anything less. Choosing Chatham means exceptional beauty and quality without compromises.

Chatham gemstones have gorgeous color: verdant green emeralds, velvety blue sapphires and screaming red rubies. Our gems also have lovely clarity that makes them glow with light.

a green ring a red pendant a blue ring

That famous Chatham quality is no accident: it’s the result of continuous technical refinement over our 75-year history. It starts with carefully controlling the gem crystal growth process but it doesn’t stop there. Our master gemstone cutters sacrifice 80% of the rough crystals to select only the best color and clarity. Then they carefully orient the rough gem, cutting to perfect proportions and polishing each facet by hand until every Chatham gemstone dances with brilliance.

For our award-winning jewelry collection, our master cutters have created exclusive new gem cuts you won’t see anywhere else. The romantic Flame Cut, curvy Onion Cut, elegant Elongated Pear, Oval, and Baguette cuts, and Checkerboard Antique Cushion and Barrel cuts add a fresh new look to our collections.

And our jewelry designs are just as innovative, with fluid lines of diamonds adding just the right brilliant accent to the technicolor brilliance of our gems.

At every step, our goal is the same: to create high quality jewelry that perfectly expresses your unique and colorful style. And you can feel good about the fact that our gems are better for the environment and our company is committed to social responsibility.

Since you’ll love wearing your Chatham jewelry every day, it’s also good to know you can enjoy our gems without worry, secure that they have the Chatham lifetime warranty.

life time warranty seal

our history

In the 1920s, a boy with a dream to grow diamonds began the historic experiments that would launch the world’s leading lab-grown gemstone company.

Carroll Chatham built his first gem laboratory in his family’s San Francisco garage when he was only 12.He began by trying to recreate the failed diamond-growing experiments of French chemist Henri Moissan in the 1890s.

One fateful attempt resulted in an explosion that rattled his San Francisco neighborhood, as well as the local police. To reassure his parents that the experiments were safe, he shifted his gem-growing focus from diamonds to emeralds, which require lower pressures. Many years passed with nothing to show for his attempts to duplicate the gem-growing environment in the earth’s crust millions of years ago.

In 1931, Chatham entered college at the California Institute of Technology, leaving his latest experiment still running in his family’s garage. As fate would have it, his father turned off the power supply to his project. This simple act caused emerald crystals to grow in the crucible: the first emeralds ever grown in the laboratory! It took Carroll three years to understand why the emeralds formed. When he did, he founded the company that bears his name.

After perfecting the process to grow emeralds in 1938, laboratory-grown rubies, alexandrites, blue sapphires, and orange sapphires (padparadschas) followed in the following decades. A few years after Carroll’s passing in 1983, his son, Tom Chatham, finally achieved his father’s lifelong dream of growing diamonds in the laboratory.

Tom’s continued fascination with gemstones and crystal formation resulted in the introduction of several other lab-grown stones: opal, morganite, and aqua blue spinel.

Today, Chatham is still recognized as the leader of laboratory-grown gemstones. The company’s Lifetime Warranty and Certificate of Authenticity assure that Chatham-created gems will continue Carroll’s legacy for generations to come.

first chatham grown crytal on 1936 First Chatham grown crystal, 1936
Carroll Chatham's childhood home 1930 Carroll Chatham's childhood home 1930
5 crystals
chatham family 1947 Chatham Family 1947
Carroll Chatham 1948 Carroll Chatham 1948

Chatham through
the years

Times change, but Chatham has remained the world’s favorite created gemstones. Here are a few of our favorite ads and articles from more than 75 years of history.

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giving back

Chatham has a long history of continuous support for education and gemological research. We’re proud to have contributed more than $1,500,000 to museums, educational and research institutions, and charities.


In the 1950s, our founder Carroll F Chatham was asked by the Smithsonian Institution to grow the largest emerald he could. He spent three years growing a crystal that was more than 2,000 carats, about the size of a baseball, which he donated to the museum’s collection.

Chatham Museum Donations
  • American Museum of Natural History
  • Harvard Museum
  • Museum of Mineralogy in Hamburg, Germany
  • Museum of Idar-Oberstein
  • Natural History Museum of Los Angeles
  • Smithsonian Institution
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One of Chatham’s core values is the continuing education and professionalism of the jewelry industry. We are strong advocates of consumer protection through truth and disclosure. We have donated over $500,000 to the Gemological Institute of America, the world’s leading gemological educational institution. Through our support, students have been able to study our crystals and gemstones for clearer identification between lab-grown and naturally-mined gemstones. Our support of GIA research has helped to further the frontiers of gemological knowledge. Chatham’s donations have supported the GIA, GIA Alumni Association, and GIA Japan.

Tom Chatham has also personally donated his time, providing global lectures on growth of gemstones and diamond for more than 30 years. He has personally given away over 20,000 Chatham crystals to further promote education.

Chatham Professional Association Donations
  • American Gem Society
  • Asian Institute of Gemological Science
  • Brazilian Gemological Association
  • Brazilian Institute of Gemology and Mineralogy
  • Canadian Gemological Association
  • Gemmological Association of Great Britain
  • Gemmological Association of Hong Kong
  • Gemological Institute of America
  • Revere Academy of Jewelry Arts
  • Women’s Jewelry Association
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Chatham is a constant supporter of higher education. Our goal is to inspire young professionals to pursue careers in the jewelry industry. Chatham has sponsored the annual Gem Grab Bag auction at the University of Maryland, which funds student grants. This initiative, which benefits the Maryland Parents Association Student Scholarship Fund, helps students who face financial hardship and are at risk of not being able to complete their education. So far we’ve been able to grant Chatham scholarships to more than 25 students.

Chatham University Donations
  • Iowa State University
  • Northeastern Illinois University
  • Oklahoma State University
  • University of Hamburg, Germany
  • University of Maryland


Chatham Research Laboratories has been an ongoing member and supporter of the American Crystal Growth Association. To further research in the development of ruby lasers and computers, Chatham donated many crystals to the association in the 1950s and 1960s. This resulted in our emeralds being sent to the planet Mars within the Rover dune buggy helping to analyze the geology of the red planet.

Chatham Scientific and Charitable Donations
  • American Crystal Growth Association
  • City of Hope, Louisiana
  • NASA
  • Vietnam Veterans of America

Why Consumers Choose Chatham

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In Their Own Words

What does it feel like to wear Chatham? These consumers from across the country were kind enough to drop us a line to let us know how they feel about their jewelry. We’d love to hear from you too! Send us an email to share your story.


Customer for life

I love my Chatham necklace. Not only is the design absolutely beautiful, but the value is unsurpassed. You’ve got a customer for life! – Susan L., OH


Engaged in Sapphire

My boyfriend and I originally planned to go ‘engagement ring window shopping’ just to see what was out there. All I really knew was that I wanted a sapphire engagement ring, more intricate than a solitaire but not over the top. When we finally made it to a local retailer I had wanted to go to, most of what we saw seemed like things we had seen before. We were explaining to the woman behind the counter that we were planning on purchasing a lab-created sapphire to bring it to be set in a ring when she stated, “Oh, you want a Chatham Sapphire.” She went to another counter and returned with the most gorgeous ring, and I fell in love. It was beautiful, affordable, and truly unique with its Onion cut design (which we had never seen before). My boyfriend sent me out of the store to make the purchase, and the rest is history. – Catherine H., MD


Blue Diamond AND a Vacation!

I purchased a blue diamond Chatham ring for my wife. She was absolutely thrilled. I’ll never forget the look on her face. The quality is phenomenal but the best part is that I could still afford the vacation we took when I gave it to her. Thanks! – John F., FL


Modern Emerald for Her Birthday

My girlfriend wanted something special for her birthday, and a friend told me about Chatham created gemstones. My local retailer sold me a beautiful emerald pendant with a modern design. She loves the pendant, I love the price, and we both love the unsurpassed quality. – Nathaniel W., NY


Telling All My Friends

When my husband first told me about Chatham I was skeptical. However, after learning more about the process I decided to check them out. Once I saw Chatham jewelry in-person I knew that I’ll never purchase a mined stone again. I’m telling all my friends about your beautiful gemstones. – Sharon V., CA


As Blue as the Ocean

I love, love, LOVE Chatham. I got my first real Chatham ring today for my graduation present for graduating high school. It’s a blue sapphire the color of the Hope Diamond from the Titanic movie in a teardrop shape with diamonds surrounding it. I love it and have already gotten a ton of compliments on it. My mom said that it looks like it should be an engagement ring and I am already planning to possibly make it into my future wedding ring or possibly my daughter’s engagement ring. (40 years from now. No kids for me for another 8 years at least. LOL.) I love my ring and always will and it has more sentimental value to me than the price. (which we all know is crazy high but oh so worth it.) – Taylor S., OH


Decades of Beauty

I purchased a 3 carat green emerald cut solitaire ring in 1988 and it was absolutely beautiful. I have received so many compliments on my ring. Today, my ring is as beautiful as the day I bought it. – Linda C., TX


Our Retailers

We’re proud of our gemstones and want to make sure that everyone who wears one gets the chance to learn all about it.

That’s why we partner with the best independent retailers in America to carry Chatham brand jewelry.Your local independent jeweler is part of your community, a supporter of local causes, and invested in helping your community and its people grow and prosper.

Find a retailer near you