neat theory, even if it's still easier to make them in a local oven ...
Diamonds may stud Mercury’s crust
Billions of years of impacts may have turned much of a graphite crust into precious gemstones
[sciencenews.org]
The Only reason Diamond's are still considered "precious" is Marketing and and a Monopoly on mining and processing them. Think house of Rothschild..
Good point. Now De Beers is all over the place with an ad campaign to get people to prefer their mined diamonds to synthetic ones.