i know a lot of jewelry stores will put “grades” on pearls as well. here is a helpful article about the different grades of cultured pearls that you might enjoy

The list was very informative and helpful. Thanks for sharing! I just wish that I could gauge how much smoother a salt water pearl rolls vs a salt water pearl – because I have freshwater pearls and I think they roll pretty smoothly! Also, when you’re shopping for pearls, do the salespeople let you just rub the pearls together? Wouldn’t that damage it?

I’m a real pearl lover, so if it’s okay I’ll just add this:

Freshwater pearls are made by mussels, saltwater pearls by oysters. It takes years to produce a good marine pearl, and a much shorter period to produce freshwater pearls.

Differents species of oysters make different pearls — this wiki article has a good list of the species and the pearls they produce: http://en.wikipedia.org/wiki/Pearl_oyster

Size does matter, but pricing is related to both size and quality, particularly with saltwater pearls.

I think there are times when uniquely shaped pearls are worthy of a good price — when they are saltwater keshi pearls — accidents of nucleation. (This is a nice bit on keshi pearls: http://www.pearl-guide.com/keshi-pearls.shtml)