There is something very dazzling about pearls, almost sacred... For one thing they start off by being sand and mollusk. Basically, a pearl is produced when an irritant such as sand gets caught inside the oyster. To protect itself, the oyster secretes a substance similar to mucus. This substance builds up around the sand and hardens. The end result is a pearl.
They vary in shapes, sizes and even color. Thanks to modern man... we can manipulate it's process to amazing results. Different parts of the world come up with diverse kinds of pearls, some more unique then others. Natural or South Sea pearls are those made by mollusks harvested from the ocean. Every now and then, one of the pearls will be a shade darker, either gray or black. These are rare, and as a result, very expensive.

Cultured Freshwater Pearls
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 pearl and shell were used for decorative purposes on articles of clothing. Freshwater pearls are best known for their whimsical shapes and wide range of sizes and colors. As freshwater pearls are composed of solid nacre, these pearls are sure to last a lifetime. 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 the most common color, the most desirable are the pastel pinks, roses, lavenders, and purples. The different colors are a function of 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. Problems can arise in putting together matched strands because of the wide range of pastel colors.

Cultured Akoya Pearls
Timeless pearls for all generations - Cultured Akoya Pearls. The beautiful luster and perfectly round shape of high quality Akoya pearls are the classic and most desired of all cultured pearls. Akoya pearls are the specialty of Japanese pearl farms. The first pearls to be cultured early in the 1920s, their white color and rosé overtone complement a fair complexion. You may notice that the Akoya looks very similar to the Freshwater pearl. When compared side-by-side, the difference is clear. Besides being more expensive, Akoya pearls are on average larger, smoother, rounder, and more lustrous than Freshwater pearls.

Tahitian Cultured Pearls
The natural black color of these pearls comes from the color of the oyster's black lips. These cultured pearls are cultivated from the black-lipped variety of the pinctada maxima oyster which reaches a foot or more in diameter, and produces very large pearls. This oyster is very sensitive to the pearl culturing process, which makes the pearls very costly to produce. A gift of Tahitian cultured pearls makes an extraordinary, unique gift.

Hope that gives you a better perspective on the power of pearls. I've always loved them, their great ability of evoking elegance has attested through timeless ages and today we see that they are still a special part of jewelry decor as ever.