Pearls are gems produced by salt water oysters (the non edible variety) or by freshwater mollusks. The gems are available in a variety of shapes, colors sizes and grades. The quality of the gem is based on five main criteria: luster, cleanliness, shape, color and size. Based on these five determinants, the gems are graded into various categories such as A, B, C, etc. Grade “A” is the highest. Grade A gems have few or no blemishes and exude high luster. The nacre determines the luster of the gem. The nacre is the substance that the oyster secretes to coat the nucleus.

A gem with excellent luster will have a thick nacre coating the nucleus giving it a lustrous and milky like quality. Usually, gems with high luster give off flashing rainbow colors called iridescence. This feature is also known as Orient. The brilliant orient is due to the fine quality of the nacre. It is this particular feature that makes salt-water gems more expensive than their freshwater counterparts.

A pearl’s cleanliness is its freedom from skin blemishes such as pits, spots or blisters. Perfectly spotless gems are rare. Most gems will have some kind of blemish or imperfection. Very small defects in the gems are acceptable. However, large defects are unsightly and they lower the gem’s value. A clean gem without surface imperfections is graded higher than one with spotted imperfections.

The gems also come in a variety of naturally formed shapes, including off-round, drop-shaped, button-shaped, baroque, semi-baroque, and circlé. Because round gems are valued for their perfect symmetry, they are generally graded higher than other shapes. However, depending on preferences, other shapes may be more desirable for their unique appearance.

The most desirable color for cultured pearls is white with a rose overtone. Gems with cream-colored overtones are also desirable. Gems with yellowish or greenish overtones are less expensive. The gems occur in many natural colors, such as pink, green, golden, gray, blue, and black. Pearls of natural color are pricier than their white counterparts.

The gems are sold by their millimeter price. The larger the gem, the more it costs. Because large pearls are rare, any gem in excess of 15mm is treasured and commands a high price. The value of the gem typically appreciates with size. For example, a 1mm increase in the size of a medium-quality gem can raise its price by 100 to 200%.

Pearls make a versatile gift for many different occasions, such as weddings, anniversaries birthdays, Valentine’s Day and graduations. They are a popular choice for brides on their wedding day. The opulence and beauty of the gems makes them the perfect accessory for any bride. White pearls especially have been recognized as symbols of purity, modesty and chastity, thus the ideal jewelry to be adorned by the bride on her wedding day. Pearls also make great gifts for bridal parties and mothers-of-the bride and groom.