Gems by Geography: Exploring freshwater pearls
This month’s Gems by Geography journey is a two-for-one stop. Welcome to Kentucky and Tennessee as we explore freshwater pearls – the official state gemstone of both destinations.
Interestingly, freshwater pearls are not typical gemstones. Gemstones are usually minerals. Pearls are deposits of calcium carbonate called nacre. Pearl (nacre) is not a mineral in part because it is formed by a living organism. But, since pearls have long been used in jewelry, they made the cut.
Natural freshwater pearls were historically found throughout the Mississippi and Tennessee River valleys, but over-harvesting, pollution and damming of these rivers depleted the population of natural pearl-producing mussels.
Today, mussels containing pearls are cultivated through man-made processes on "pearl farms" along Kentucky Lake in Tennessee.
Little known pearls of wisdom
- Different species produce different colors and shapes.
- It takes 2 to 3 years to cultivate a pearl.
- Natural freshwater pearls are seldom perfectly round or even nearly round.
A bit of history
Native Americans of the Atlantic Coastal areas and the Mississippi River Basin were the first to collect and use U.S. freshwater mussel pearls and shells.
Pearl pendants and ear pendants were worn by both sexes and both the pearl and shell were used as decoration on clothing. In addition, armlets, pendants, and gaming pieces were made from mussel shell.
Freshwater pearls are noted for their wide range of color - they can be found in white, silvery white, pink, salmon, red, copper, bronze, brown, lavender, purple, green, blue, cream, and yellow. Although white is most common, the most desirable colors are often pastel pinks, roses, lavenders, and purples.
The different colors are attributed to the mussel species, genetics, water quality, and the position of the pearl in the shell. Generally, pearls assume the color of the shell in which they form. As you can imagine, because of the wide range of pastel colors it can be challenging to put together a matched strand.
Rough pearls in the shell (Source: www.atoztheusa.com)
Kentucky is known for more than its pearls. What else comes to mind? The Kentucky Derby, of course. Here are Horseshoe post earrings with pearls. (Source: www.derbymuseumstore.com)
Pearl necklace featuring unique colors and shapes of each pearl. (Source: About.com)
Visit our jewelry care and cleaning page and learn how to take care of you pearl jewelry.