By Russian Lab diamonds, do you mean the ones that are made "synthetically," but in the original, natural way (compressing an amount of carbon)?
I remember a while back on PBS, there was a NOVA episode where they talked about these synthetic, but real-looking diamonds (I don't remember if they were Russian).
Here's a site from the Russian labs themselves (although I guess it's hard to tell if it's just marketing or otherwise):
Synthetic Diamonds, Diamond Synthetic, Cultivated Diamond,Simulated Diamond Jewelry and More
Here's a good consumer report magazine article:
Wired 11.09: The New Diamond Age
Good luck!