HPHT stands for high pressure, high temperature. HPHT is applied to premature diamonds that are not fully crystallized when released from volcanoes.
HPHT mimics the exact same conditions that occur in the volcanic environments where diamonds are found. This process brings a candidate diamond to its most desirable, colorless, and mature state. Mature diamonds are defined as those that show a highly coveted D, E, F, G or H color grade. The HPHT process simply finishes what nature started.
The HPHT process is a carefully controlled, scientific procedure where high pressure and high temperature is used to apply the same atmospheric pressure (70,000 atmospheres) and temperature (3,682°F) conditions required to bring a diamond to its fully mature state. To do this, gemologists position a suitable diamond in a "containment cube" that is surrounded by heating mechanisms. The cube is then placed in a press to apply the same amount of pressure the earth creates when forming diamonds. These multi-million dollar facilities are very sophisticated and are centered around an enormous computer controlled diamond press.
Only superior grade, Type 2 a, TLB and TTLB diamonds are candidates for HPHT. These diamonds must have clarity grades of FL-VVS2. HPHT diamonds are not synthetic or treated diamonds. HPHT diamond processing does not involve chemicals, are not irradiated or coated. The HPHT diamond maturation process is permanent.
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