Knowing where a diamond comes from?

Diamonds are pure carbon with minor impurities. You can guess, but not 100% sure where a stone comes from by certain impurities, like tinted stones, also known as caped stones, because S.A. used to produce the majority of these but not all comes from there. From rough, additional info can be gained, such as what kind of deposit it comes from, but once polished, you loose that info.

All polished stone will be conflict free under the kimberly process, else it will be illegal.

Spirit, what do you mean by "conflict free," and why do you want that?

Ira Z.

P.S. Though I support the purported effort you'd be making, I fear the premium mentioned is even conservative...at least at smaller sizes.