Okay, you’re ready to pick the perfect string of pearls. Print this list out and take it with a jeweler’s loupe and a soft cloth on your shopping spree! And have fun.

1. Assume all pearls are cultured. If a jeweler insists they are natural, get documented proof.

2. Nacre thickness: look for the inner glow, orient, look into the drill hole with a loupe (see a brown line? thin nacre) Still not sure? get the pearls X-rayed.

3. Luster and Orient: Observe the pearls under a fluorescent light. Watch for the direct shine, and the "ball" of shadow that indicates nacre thickness. Orient is the iridescent quality famous in natural pearls, but rare in cultured pearls because of the amount of nacre required to produce the effect.

4. Pick any color you like. Think in terms of what compliments your skin tone and hair color. Remember "body color" and "overtones". If you want traditional white pearls, look for white-pink (most valuable) if you prefer black, think black-green.

5. Round pearls are most valuable, but whether you choose spherical, symmetrical or baroque shape, think in terms of matching pearls on a string. That’s where shape plays a role in value.

6. Cultured pearls are sold by size not weight. Think millimeters.

7. Always ask your jeweler if any luster or color enhancements have been performed on the pearls. If so, that’s okay, as long as no harsh chemicals have been used. Make sure to get all treatments and enhancements clearly written on your bill of sale.

So, there, in an oyster-shell, is what you need to know, keep in mind and ask about as you shop for what could very well be the most treasured possession you’ll ever own.