• Nacre is the substance that gives pearls their luster.
• The thicker the nacre, the better the pearl.
• Cultured pearls are real pearls.

The modern pearl market is possible because of one thing: Culture. For centuries, people have been trying to unlock the secret of nature and duplicate the magic worked inside a particular type of mollusk that is actually more closely related to the scallop than the oyster of pearl’s lore. But it wasn’t until 1916, when Kokichi Mikimoto patented his technique for producing round pearls, that the world was offered the means to enjoy and appreciate an abundance of these gems from the sea.

Unless you are shopping at estate sales or antique auctions, virtually all the pearls you see are cultured pearls. But cultured pearls are real pearls, they’ve just gotten a little help from science.

It’s funny to think that the pearl producer’s job is to irritate oysters, but that’s exactly what they do. Planting a mother-of-pearl nucleus into the soft membrane of the "oyster" kick-starts the mollusk’s natural protective response which is to secrete a conchiolin (soothing brownish substance) followed, and covered, by a nacre coating (the lustrous materials of pearls) to destroy the intruder. The longer it cultivates, the thicker the nacre. The thicker the nacre, usually, the deeper the luster. The deeper the luster, the better the pearl.

Even though cultured pearls are real pearls, there are a couple tests you can do to determine the difference between cultured and natural.

1. Look at the drill hole. Natural pearls are composed entirely of nacre, while cultured pearls are nacre surrounding the mother-of-pearl nucleus. This point of connection between the nucleus and the nacre can be seen as a dark brown line when examined carefully through a jeweler’s loupe. This is not a foolproof test, though, because some cultured pearls have such a beautiful, thick nacre that the brown line will not be visible. This line can also be bleached away. Therefore, if you don’t see a brown line, more testing needs to be done.

2. Ultraviolet test. Under a regular black-light, natural pearls will typically emit a yellowish-tan fluorescence, and cultured, a milky-bluish color.

There are also fiber-optic and X-ray tests that any gemologist can perform for you which are fairly foolproof in spotting nature from nurture.

These tests are not necessary unless you are looking at antique jewelry or if a jeweler tells you his pearls are natural (in which case, make sure he has documentation to back up his claim.)

Cultured pearls have literally saved the pearl trade from extinction. If it weren’t for cultured pearls, only kings and queens and the fabulously wealthy would be awarded the opportunity to treasure these gems. Thanks to Mr. Mikimoto, we can all marvel at the inner glow and magical beauty of pearls.

Answer to quiz: b