[cr0sh]

> The general opinion is this is a synthetic diamond laundering operation.

If this is true, then the Soviet Union must have come up with an alternate method to produce "tons" of these high quality, large diamonds long before anyone else:

https://en.wikipedia.org/wiki/Synthetic_diamond

The two methods then known to make synthetic diamonds, were only useful for industrial diamond purposes, if I'm reading that correctly. It seems like another alternative process wasn't created until the 1990s. It also seems like none of these (?) known processes are useful for gem quality diamonds, or if they are, they can't make such diamonds of large size in large quantities.

If the then-Soviets had this technology - and still have it - it would be a massive disrupter to the entire diamond trade business. I would imagine that even for industrial diamonds, it would still cause problems (you know, problems like lower prices and better availability).

[ericfranklin]

Correct. The Soviet technology for growing diamonds is HPHT (high pressure high temperature). There are a handful of known producers and research facilities in the former Soviet Union that can grow diamonds, but all using HPHT. These were all industrial grade until the late 90s-early 00s, and colorless diamonds did not consistently grow with this technology for several more years.

The other technology you mention is CVD (chemical vapor deposition), which was not developed in Russia, and was not commercially viable for gem-quality diamonds until the last decade either.

[BoiledCabbage]

> These were all industrial grade until the late 90s-early 00s

I believe the point being made is that the only ones publically admitted to being lab made were the industrial grade. The lab made gem grade were made to look like mined stones. The belief is the Soviets kept this a closely guarded secret because it was very profitable for them.