What Is High Pressure High Temperature (HPHT) Color Treatment?

HPHT stands for high pressure and high temperature. It is a method of applying HPHT to those diamonds that are not fully crystallized ("premature diamonds") when released from fiery, erupting volcanoes. The HPHT process is a scientific procedure that is carefully controlled. The HPHT process is used to finish what nature started by applying 70,000 atmospheres (the same atmospheric pressure that a diamond gets in the ground) at temperatures up to 3,700°F.

Meeting these conditions will bring a diamond to its fully "mature" state. The HPHT process involves the careful positioning of a diamond by a highly trained gemologist into a "containment cube" that is surrounded by heating mechanisms. The cube is then placed in a press to apply the same amount of pressure that the earth creates when forming diamonds. This process brings the diamond to its most mature, desirable, colorless state. Mature diamonds are defined as those that have D, E, F, G or H color grades. The HPHT process simply finishes what nature started.

The HPHT diamond maturation process is permanent. Even though heat and pressure is applied to bring a natural, high clarity, top light brown (TLB) or top, top light brown (TTLB) to a white color grade, it is important to note that these diamonds are not synthetics and are 100% natural diamonds.

Diamonds in the 3 stages of HPHT treatment process

The HPHT color treatment process can be only be applied to diamonds of the highest clarity such as: VVS1 VVS2VS1 VS2. The diamonds must also be flawless, due to the fact that during the process diamonds with inclusions and fractures can be broken and surfaces can be become frosted. Even the very slight inclusion can blow up the stone during the process, thus rendering it useless.

The HPHT process is the only permanent color enhancement process, the only treatment that completely saturates the diamond with color. Unlike irradiated and coated diamonds (another commonly used process to improve the look of diamonds), HPHT diamonds are impervious to change and need no special care to maintain their resilient color. In contrast, irradiated diamonds are prone to color fading at high temperatures and both irradiated and coated diamonds cannot be polished or recut without affecting their color.

What Are The Advantages Of Buying An HPHT diamond?

  1. The major benefit of buying an HPHT natural diamond is having the ability to purchase the highest clarities and white diamonds with average savings from 45-70%. For example a round 1.51 carat D VVS1 natural diamond that costs approximately $32,700 online where the same diamond treated by the HPHT color process sells on CaratsDirect2U.com sells for $11,415 that is a total saving of $21,285 (approximately 65%)!
  2. Colored diamonds while being very popular and desirable are very rare and extremely expensive, making them affordable only to a select few consumers. Now with the HPHT process they are affordable to everyone.
  3. HPHT treatment is a process which is very similar to nature, putting the diamond back into the environment in which is formed.

In short HPHT diamonds are genuine, mined diamonds. They are suitable for diamond buyers who want top color and clarity, at a substantially lower price, with GIA or EGL certificates.

We at CaratsDirect2U, carry a large selection of ½ carat, ¾ carat, 1ct, 1.5ct, 2ct HPHT Diamonds In Round, Pear, Heart, Marquise, Triangle Shapes as well as in clarities ranging from I1 until VVS2. We also carry the very sought after Pink colored HPHT diamonds such as a 0.71 carat VVS2 clarity fancy pink round shaped diamond, which would look great mounted in a 14 karat white gold as a solitaire pendant.

Check out our collection of HPHT loose diamonds.

All of these diamonds are available as loose diamonds as well as mounted in any of our 14k or 18k White, Yellow, Rose, or Two-Tone Gold engagement rings, pendants, or stud earrings. Please call one of our expert jewelers toll free at: 1-800-557-7095 if you have any more questions about out HPHT diamonds.