Natural, Real, Synthetic, Simulated - What's the Difference?

Shopping for gemstone jewelry is confusing, isn't it? Prices are sometimes very different for jewelry that appears to be made with identical gemstones. You'll see ads that describe gems as natural, genuine, synthetic, simulated, treated -- or a combination of those terms. Before you buy, be sure that you understand how to sort through the terminology to find out how the differences (should) affect jewelry prices.