Related topics: lab-grown diamonds, synthetic diamonds, HPHT diamonds, man-made diamonds, eco-friendly, conflict-free

The New Diamond Technology company, based in St. Petersburg, Russia, once again announced its success in growing large colorless nitrogen-free type IIa single diamond crystals using HPHT technology.

The team, consisting of two doctors of science – Dr. A.Katrusha and Dr. A.Koliadin, and technician R.Isakov, grew one of the largest colorless nitrogen-free crystal weighing over 32 carats in record growing time of 300 hours.

The previous record was set by De Beers group that grew a big nitrogen-containing diamond weighing 34.8 carats (type Ib, yellow), which can be described as technical quality stone, in 600 hours. 

The New Diamond Technology was able to achieve excellent results by growing a crystal of 20.69 mm in length with a width of 17.53 mm and a height of 11.80 mm. The crystal, weighing 32.26 carats in total, was grown using an experimental technology, and therefore has minor flaws. In the lower part of the crystal body there are such defects as twinning and parallel expansion, but the top portion (more than 2/3 of the diamond) still formed a fine monocrystal.
It is possible to get a polished DF-color and VS-clarity diamond crystal weighing about 8 carats from it, or it can be machined into a set of wafers for the electronics industry and CVD matrix.

Dr. B.N. Feigelson, a well-known expert in the field of synthetic diamonds from US Naval Research Laboratory has expressed his opinion on the results of New Diamond Technology: "This is an important achievement. A psychologically important one. I've been convinced for a long time that growing large HPHT diamonds is not just a real thing, but it is economically feasible and necessary. Linear growth rate of the crystal demonstrated by the company makes this a good result that is particularly impressive and important."
Analysis of the parameters of the monocrystal leads to a promising conclusion that the weight of grown colorless diamond crystals can reach 50 carats in the near future with adequate growth time, and this technology can be the basis for the cultivation of very large gem quality crystals.