GIA's laboratory in Carlsbad, California, received 25 high-temperature (HPHT) diamonds weighing from 0.46 to 0.52 carats - including some rare green, nine of which are colorless or nearly colorless, eight are yellowish green, seven are light green, and one It is very light green.
In addition to a dark yellow-green high-temperature and high-pressure diamond reported by GIA gemologists in 2017, its color is precisely due to nickel. Prior to this, these laboratory synthetic diamonds had never been made public.
0.50 carat light green HPHT artificial diamond.
Robison McMurtry / GIA
Sally Eaton-Magaña, a senior research scientist at GIA, said: "The colour of these synthetic diamonds is caused by high concentrations of nickel (an impurity common in high temperatures and pressures), but only a few cases can affect the color (in the whole diamond, nickel can produce green Colour tone). As manufacturers of synthetic diamonds in the laboratory continue to test the formula and improve the process, a larger number and more colour range of synthetic diamonds may appear in the future. She pointed out that this identification is also a rare opportunity to analyse a large dataset of similar but abnormally colored HPHT diamonds.
We also look forward to the laboratory of synthetic diamonds to bring us more abnormally colored synthetic diamond data.