[balrog666]

Seems like, from discussion with an actual jeweler many years ago, that flawless natural diamonds are the exception. If someone turned up with a tray of flawless gem diamonds, one should assume they are all manmade. Natural diamonds have various inclusions and other defects, and color varies from one stone to the next.

True, but nobody requests inclusions and colors can be manufactured, so the top of the market will soon be dead. Where will that leave the bottom?

[RightWhale]

How is a star sports figure to atone for his transgressions when he can't buy a $4 million stone for his spouse because all diamonds now cost $1 a carat?

[DPB101]

Small, included, off-color fakes have been a lucrative business. Easier to pass off fakes in that market.