A fair amount of gold and silver you find out there is recycled, especially right now. Some of it comes from investment gold and silver (bars and coins), some from people selling their old rings.
If you want your precious metals to be somewhat less problematic, take some old jewelry to a local custom jeweler. They can melt down the old stuff and pour it into a mold. Voila, new ring, pendant, etc.
As for gemstones, I'm a big fan of lab created stones. The sapphires are incredible, the amethyst are indistinguishable from natural, and you can have a big perfect emerald that if it was not synthetic, would be a museum piece, all for a fraction of the cost of natural. There aren't any good synthetic tanzanites yet, and while lab created diamonds are flawless, they are almost as expensive as mined stones. Lab created stones are only lacking as investment pieces, and perhaps to people who want the sentimental value of a "real" stone.