Chatham, as used in gemological conversation, stands for a manufacturing technique of synthetic gemstones. The method incorporates crystallization of a gem material from a solution in a flux rather than from molten ingredients such as the flame fusion or Czochralski method. Its inventor, Carrol Chatham, tried to mimic the situation (certain) gems form in nature. Deep in the earth's crust temperatures and pressures are allowing water to hold higher quantities of minerals in solution than here at the surface of our planet. When these hydrous solutions rise, they cool and enjoy lesser and lesser pressures, causing the chemical elements to come out of solution and crystallize to become gemstones and minerals as we know them. Bypassing the necessary immense pressures Chatham used a flux to create super saturated solutions.

Some important gem minerals that can (and are) produced by the flux-melt (or Chatham) method are:

Chatham Story

source: Chatham Website

In the late 1920's a young boy followed his dreams in what was to become one of the world's preeminent crystal growers. Carroll Chatham took his avid interest in chemistry and pursued his dream by endeavoring to duplicate nature's process to create a diamond. Chatham was intrigued by chemistry and created a lab in his family's garage at the young age of 12. He learned by trial and error, making fireworks and smoke bombs for his amusement. He read of failed attempts by Henri Moissan to make diamonds, and replicated his 1890's experiments.

One attempt resulted in an explosion that rattled his San Francisco neighborhood, as well as the police. To calm the police and his parents, he shifted his focus to growing emerald crystals, hoping a crystal formation would not require immense pressure. Many years passed with nothing to show for his on and off again attempts to duplicate what happened in the earth's crust millions of years ago.


In 1931, Chatham entered college at the California Institute of Technology, leaving his latest efforts in his family's garage still running in his absence. As fate would have it, Chatham's father turned off the power supply to his science project. This simple action caused his emerald crystals to grow in the crucible, and the legacy was born. It took Carroll another 3 years to understand why the emeralds formed! When he did, he never had another failure.

After emeralds in 1938, rubies, alexandrites, blue sapphires, and orange sapphires all came to fruition over many decades of research in the hands of Carroll Chatham. A few years after his passing in 1983, his lifelong dream of diamond cultivation finally became a reality for his son, Tom.