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The Planetary Gemologists Association Global

123-C All Season Place, 87/208 Wireless Road, Lumpini, Bangkok-10330, Kingdom of Thailand 02-252-1230 • E-mail:


Dr. Shekhar Vashishtha

B.Sc.(Hons.), M.Sc.Applied Geology, B.R., S.S., P.G.D.J., Ph.D.
C.C.F.S., F.G.S., G.G(U.S.A),F.G.A..(U.K.), P.G. (THAILAND)

The High Pressure High Temperature (HPHT) treatment has been a controversial topic of discussion in the gem world and will remain in future. The HPHT treatment is a process developed by General Electric Company used for diamond color modification that uses to grow synthetic diamonds. This treatment eliminates the brown color by reducing or removing the structural distortions or irregularities in some IIa diamonds. The HPHT treatment may dramatically improve the color and value of brownish diamonds. Brown diamonds of N to O color on Gemological Institute of America (GIA) color classification system and even fancy light brown diamonds may be converted into colorless or near colorless diamonds -. D to H grades by an annealing process involving HPHT technique. Type Ia diamond color have yielded fancy Greenish Yellow and Yellowish Green color. Pink and Blue color diamonds have been produced by the same process. General Electric is producing colorless diamonds called Bellataire from type IIa diamonds that are nitrogen free.

The HPHT treatment in diamonds is permanent Most HPHT treated diamonds are over 0.50 carat. The color enhanced diamonds with HPHT treatment are reaching in trade undetected and are being sold for a much higher price. The HPHT treated diamonds should cost less than similar natural diamonds.

The various gemological tests including high magnification, Conductometer, Geiger Counter, X – Radiography, X – Ray fluorescence, Ultraviolet fluorescence, X – Ray diffraction, Infrared absorption spectroscopy, Photoluminescence techniques etc. may be used to identify a treated or irradiated diamonds.

The Federal Trade Commission states that HPHT treatment must be disclosed. General Electric uses a registration number and the letters. “GE POL ” to inscribe their diamonds. The diamonds that are laser inscribed with words – “HPHT PROCESSED”, IRRADIATED or a specific registered name are graded in gem testing laboratories. On detecting HPHT treated diamonds, GIA certifies the same as “HPHT Annealed” or Artificially Irradiated in their grading reports.

Astrologically speaking, only diamonds of natural origin should be used in astrology.

On doing treatment on Diamonds the energy gets liberated . The Diamond becomes free from its Soul, Pran, Atma and thus gets polluted or destroyed. Then it is charged with negative energy which is not useful in astrological application. The treated diamonds do not serve any purpose for astrological effects and gains

The Sanskrit name for the PGA was composed by HONORARY PATRON Prof. Dr. Satya Vrat Shastri, Padma Shri