That’s just my opinion, but check this out: Or, as scientists say: Sometime after the rock formed . . . an asteroid impact blasted it
There have been some interesting news stories recently about ancient water here and on Mars. They are hard to describe in plain English, though–at least
Diamonds aren’t the only mantle-associated gems. Most of the upper mantle is made out of peridotite, a combination of olivine and pyroxene. It is named after the very famous gemstone it contains–peridot.