Among the various types of gem treatments practiced today, the heat treatment of ruby and sapphire is the most common and most important. Rubies and sapphires heated under certain conditions in order to improve their color and/or clarity, thus increase their value. The results after the heating vary widely and depending upon the type of material, ratio/type of the color-bearing impurities, heat treatment technology, heating method applied, equipment used and other parameters.
For those individuals wishing to serious study the heat treatment of ruby & sapphire may attend our special 6-day "on-hand" practical course offered periodically several times per year in our heat treatment laboratory premised in Bangkok. Details click here.
Those wishing to read more about he subject can buy our book "The Heat Treatment of Ruby & Sapphire- SECOND EDITION". Click here for details.
The most common heat-treating processes applied to ruby-sapphire as defined by Ted Themelis using his heating technology and methodology developed over the last 30 years as described as follows: