HPHT Basics

We, at Teva Diamonds, have discussed HPHT Diamonds. (click here) However, we wanted to delve a little further into the specifics or the “basics” of HPHT Diamonds.

Not every diamond mined is perfect. Some need a little help to achieve their predestined beauty. HPHT or high-pressure, high temperature, diamonds are 100% natural diamonds with a unique chemistry that allows for a distinct color change. HPHT diamonds are not lab-created, synthetic or human-made. The art of using advanced HPHT technology allows a diamond’s color to be changed through treatment. The Diamonds selected for High-Pressure High Temperature (HPHT) processing are rare and must be of high quality. Only 2% of the diamonds available on the market today meet or exceed the standards for color change. Not all colored diamonds are HPHT processed. Naturally, colored diamonds are rare and extremely valuable. A 1-carat pink diamond can sell for millions.


The HPHT process entails exposing high-quality diamonds, that meet our strict standards, to extreme heat and pressure. By extreme heat, we mean temperatures near 5000°F. Heat is used to expose the true nature of the stone, which results in the color the diamond was intended to have. Extreme pressure is used to maintain the natural form of the diamond. If the high pressure were not applied, then the diamond would revert to its original form of carbon, graphite.


Not every diamond is suitable for the HPHT process. The type of diamonds suitable for the HPHT process fall under the Type IIa category. Only 2% of all naturally occurring diamonds are Type IIa. What are Type IIa diamonds? Diamonds are classified according to their molecular structure differences. Type IIa diamonds, once mined, contain a brownish tint from the constant exposure of minerals and soil, resulting in chemical reactions. The HPHT process desensitizes the diamond and allows it to obtain its predetermined color.

HPHT is a permanent process, and the diamonds will keep their color and appearance.

Learn more from the Teva Diamonds experts. (877)683-3426