What Should You Know About Pearls You Already Own?

Inherited and older pearls usually raise the same few questions: what they are, what condition they are in, and what that means for their value. The page inherited and antique pearls works through them.

Pearls or imitations#

An imitation pearl is a manufactured product that only looks like a pearl.¹ In one GIA study of imitation pearls, the tooth test was among four conclusive tests: the cultured pearls felt gritty against the teeth and the imitations smooth.² The identification section covers the other tests.

Natural or cultured#

Age alone doesn’t settle it. Cultured pearls have been commercially important since the 1920s,³ and telling them from natural pearls takes laboratory testing.⁴ A gem laboratory tells them apart with X-ray imaging: a natural pearl shows no bead or curved cavity at its center and a uniform, onion-like structure.⁵

A laboratory report states whether the pearls are natural or cultured, and whether a cultured pearl has a bead.⁶ GIA and SSEF weigh loose natural pearls in carats and in grains, where 1 grain is 0.25 carat.^{6 7}

What affects their value#

The same seven factors apply to old pearls as to new ones: size, shape, color, luster, surface quality, nacre quality and matching.⁸ Whether pearls are natural also matters, because natural pearls are rare: hundreds of oysters or mussels must be opened to find even one.⁵

Keeping them in good repair#

Over the years the string on a strand stretches and weakens, and pearls can easily be restrung.⁹ The care section explains how to clean and store them.