Pearls are produced in the bodies of mollusks naturally or cultured by people with great care. Lustrous, smooth, subtly-colored pearls are jewelry staples, especially as strands. The most familiar colors are white and cream, but the palette of colors extends to every hue. The most highly valued pearls are created inside of saltwater oysters and freshwater clams whose shells are lined with mother-of-pearl, or nacre. When a foreign particle enters the mollusk’s mantle, shell-secreting cells attach themselves to the particle and form a protective barrier. The resulting pearl is measured in grains and is more sensitive to elements such as humidity, acid, and dryness than other gemstones. Pearls rate a 2.5-4.5 on the hardness scale. Cultured pearls are essentially the same as those found in nature, the only difference being that a foreign particle is intentionally inserted into the mollusk with the express purpose of creating a gemstone. People have coveted natural pearls as symbols of wealth and status for thousands of years. Pearl is the birthstone for June, together with alexandrite and moonstone. It makes a traditional gift for 3rd and 30th wedding anniversary.
There are four major types of cultured whole pearls:
- Akoya -This type is most familiar to many jewelry customers. Japan and China both produce saltwater akoya cultured pearls.
- South Sea – Australia, Indonesia, and the Philippines are leading sources of these saltwater cultured pearls.
- Tahitian – Cultivated primarily around the islands of French Polynesia (the most familiar of these is Tahiti), these saltwater cultured pearls usually range from white to black.
- Freshwater – These are usually cultured in freshwater lakes and ponds. They’re produced in a wide range of sizes, shapes, and colors. China and the US are the leading sources.