[JamesP81]

Well, the quantity is so vast (larger than the Earth itself by orders of magnitude) that the price of diamonds would plummet.

That's OK as long as you get there first and make the money before the price drops.

[SunkenCiv]

And of course, catering to the more-money-than-brains crowd (i.e., the entertainment industry and OPEC billionaires) would help — “a 200 foot yacht built entirely out of diamond? No problem...”