No one has ever asked me if the gold in a ring has been freshly mined. No one has ever asked me if the natural diamond they're buying was freshly mined either.
People do ask about gold all the time though. They want to know if it's "pure gold". They want to know if 10k, 14k, or 18k is better. They want to know if it will "turn their finger green".
People do care what they're buying, especially when they're spending a lot of money and presenting it to someone they love, which is usually the case in the jewelry business.
You've alluded to unethical diamond mining practices several times. I'd encourage you to read up on The Kimberley Process. Jewelers are human beings too and we are typically far more ethical than people give us credit for.
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