[atemerev]

Doubtful, for several reasons:

1) Synthetic colorless gem-grade diamonds are difficult to make (they can be produced today, about 2-3 times cheaper than natural diamonds, but in small quantities -- and synthetic industrial-grade diamonds are also quite profitable, with significantly larger and accessible market -- but much easier to create).

2) Synthetic diamonds are relatively easy to identify (with microscope and ultraviolet light source)

3) Even today, Russian-sourced gem grade diamonds are somewhat less diverse in size and quality than their non-Russian counterparts -- and their provenance is well documented.