(ARA) - Diamonds get the credit for being "a girl's best friend," but humanity's love affair with pearls has been going on for 4,000 years -- a millennium longer than we've been digging diamonds out of the dirt.
Pearls are the only "green" natural gemstone as they are a renewable resource and are harvested, rather than mined.
While having heard about the basics of diamond buying, few of us have been educated about the nuances of purchasing pearls. Before you buy pearls, here's what you should know:

Types and Sources of Pearls
Four types of pearls are available today:

• Freshwater pearls, known for their off-round shapes, fancy colors and affordability, are almost exclusively produced in China. Prices range from as little as $20 for a strand of low-grade freshwater pearls up to several thousands for gem-grade pearls.

• First cultured in Japan nearly 100 years ago, akoya pearls are what most people think of when talking about pearls. China and Japan are the two largest producers of akoya pearls with Vietnam, Korea and Australia also producing limited quantities.

• Although known as "black pearls," Tahitian pearls come in every color of the rainbow and are prized for their large size and exotic colors. Some production also occurs in the Cook Islands, Fiji, Micronesia and parts of southern Japan.

• The most valuable of all cultured pearls, South Sea pearls are renowned for their large size and satiny luster. A large perfect strand of matched white, golden or silver pearls can cost millions. Australia is the primary producer of white and silver pearls, while the Philippines and Indonesia produce golden pearls.

How to Evaluate a Pearl's Quality
Just as you would look at the clarity, cut and carat of a diamond to determine its worth, pearls have value indicators as well.
They are: luster, surface, nacre, matching, color and shape.

• Luster - When pearls are priced, the most factor is their luster. A high-quality strand of pearls should have a sharp, reflective quality so you are able to see your reflection.

• Surface - The pearls should be free of marks, abrasions, cracks, pits or any other imperfections that mar the surface of the gemstone.

• Nacre - The thickness of nacre - the "coating" of pearl that surrounds the bead that was inserted into the oyster - is important for saltwater pearls, especially akoya pearls. If the nacre is too thin, pearls will be chalky and not last more than a few months to a year.

• Matching - Whether as a strand of pearls, a pair of earrings, a bracelet or an earring and necklace set, each pearl in the set should match in size, color and luster. For earrings, the size should be within a tenth of a millimeter; for strands, pearls within half a millimeter to two millimeters. As a strand, pearls should also be matched from either side.

• Color - While classic white pearls will always be prized, others, such as peacock-color Tahitian pearls or rose-overtone akoya often cost more.

• Shape - Pearls come in many different shapes, from wings, to rice crispy, to potato, to round. The more perfectly round a pearl is, the more valuable the strand.

For pearl-buying advice, visit www.pearl-guide.com, or www.pearlparadise.com.

Courtesy of ARAcontent