Whenever you see pearls in a jewelry store that boast a unique color, such as white or pink or orange, it is most likely a freshwater pearl. This kind of color can occur naturally, dictated by what the mollusk eat, genetics of the creature or the type of metal found in the environment in which the pearl was cultivated.

Whether or not the color occurred naturally makes a big difference in the value of the pearl.

For example, Tahitian pearls are the only naturally occurring dark-colored pearls. While it is common to treat freshwater pearls to achieve a certain color result, it does affect the value of the stone. Therefore, colored pearls should be chosen with personality and wardrobe ideas in mind, only considering value if the color is natural.

Pearls come in variety of sizes, which helps determine the value of the stone. They are measured by the diameter in millimeters. Small seed pearls can measure smaller than one millimeter, while South Sea pearls can get as large as 20 millimeters. It only takes a one-millimeter increase in the size of a pearl to significantly increase the value and look of the pearl.

The average size of most pearls found in jewelry today measures between 6.5 and 7 millimeters. If you are looking to invest in pearl jewelry, look for larger stones for better value. If you are simply wearing pearl jewelry for fashionable purposes, size should not be a consideration.

Pearls are a delicate stone that should be handled with care. Even those with a thicker coating are fragile and need delicacy during the cleaning and storage process. Here are some tips on caring for your pearl jewelry:

• Do not expose pearl jewelry to makeup, lotions or body creams. They will mar the appearance of the pearls and diminish their luster.
• Never clean pearls with a cleaner that contains ammonia or any other harsh cleansing product.
• After every wearing, polish pearls with a soft cloth.
• Clean pearls with a mild soap product mixed with water. Cleanse the jewelry gently, being careful not to crack or scratch your pearl jewelry.

Natural pearls are much more valuable than cultivated stones. Jewelers use a special x-ray to determine whether a pearl is real or cultivated because a cultivated stone has a perfectly round sphere in the middle of the center. If that center is not perfectly round, the jeweler will know it is a natural pearl and will place a higher value on it. Imitation pearls are the least valuable and are very easily identified by a jeweler.

Some imitation pearls are made of glass and coated with a special solution to make them appear to be real. Others are made of coral or conch to make them look authentic. They do not have the same smooth quality or weight and they do not have the luster of a natural pearl. While they may have their place in your jewelry box, they certainly should not replace the experience of owning a beautiful strand of genuine, natural pearls.

Genuine pearl jewelry is strung together using a specific knotting method designed to hold pearls in place and restrict them from rubbing against one another. Without this safeguard, the pearls would not be able to maintain their famous shiny, iridescent hue.

Most pearl jewelry features knots tied between each stone. These knots are a form of security, so if a strand of pearls were to break, you would only lose one or two stones, instead of the entire strand. The knots keep the remaining pearls in place. This feature is not usually found on cheaper, costumer jewelry-style pearls.

Pearl jewelry has a special luster that sets it apart from other stones. This special luster is usually dependent on the reflection of light from the inner layers and becomes much finer as each layer of the pearl becomes thinner. The special iridescent quality that is seen in some pearls is caused by the overlapping of the pearl’s layers, which can break apart the light falling on the surface of the stone.

Pearls are usually white in color, but can carry a pink or cream-colored hue. They can also highlight tints of yellow, blue, green, purple and even black. Their unique colors usually depend on whether they are freshwater or saltwater and in what area of the world they were found.

Pearls vary in size and color, so determining the value of the stone can be difficult. Jewelers consider size, amount of flaws, luster, color and symmetry to determine a pearls value. The most important characteristics are the luster and the size of the stone. A rule of thumb is that the bigger and rounder the pearl with a healthy amount of luster, the higher its value will be.

Luster is a big consideration among jewelers placing a value on pearls. It helps to differentiate from one pearl to the next and is a significant selling point among consumers.

There are eight main shapes of pearls: ringed, button, drop, pear, oval, baroque, round and semi-round. Pearls that have a perfect round shape are the rarest of the different shapes and are usually the ones found in fine jewelry items, such as necklaces and bracelets.

Semi-rounds are only used in jewelry styles where the they can appear to be much rounder than they are. Button-shaped pearls are slightly more flat and are usually made into earrings or pendants, again covering the back portion of the pearl and giving the appearance of a round shape.

Store pearls separately from other jewelry pieces. This is for the protection of your pearls as well as the protection of your other jewelry items. Pearls can be easily scratched or broken, so keep them in a special area of your jewelry box or in an entirely different location. The best storage method for pearl jewelry is in a soft bag, made of silk or chamois or another soft fabric.

Additionally, you should restring pearl necklaces at least once every year or two to ensure that the cord holding the pearls together remains in tact.

Mother of pearl is perhaps the most popular style of pearl-like jewelry. The name describes the iridescent nacre, which is the mineral given off by the oysters and mussels that cultivate pearls. A coating protects their bodies -- and the pearls -- from any predators or random object attempting to enter the shell.

Jewelry made from mother of pearl is classified as organic jewelry, which means the jewelry originated with a plant or animal of some sort. Many cultures, both past and present, regard this pearl as one of the more valuable and colorful styles of jewelry.

Tahitian pearls are a very dramatic, sought-after style of pearl. The reason they are so dramatic has to do with their rich, naturally occurring black color, which comes from the color of the oyster’s lips. The Tahitian pearl colors can range from silver to black, with highlights of blue, purple and even green.

Tahitian pearls are produced by an oyster called the pinctada maxima, which produces very large pearls. They are expensive to produce because this type of oyster is sensitive to the cultivation process.

Tahitian pearls are a very dramatic, sought-after style of pearl. The reason they are so dramatic has to do with their rich, naturally occurring black color, which comes from the color of the oyster’s lips. The Tahitian pearl colors can range from silver to black, with highlights of blue, purple and even green.

Tahitian pearls are produced by an oyster called the pinctada maxima, which produces very large pearls. They are expensive to produce because this type of oyster is sensitive to the cultivation process.

Pearls fall into two different categories: freshwater and saltwater pearls. The difference with each directly correlates to where they are developed.

• Freshwater pearls are found in mussels that thrive in lakes, rivers, inlets and various other freshwater environments.
• Saltwater pearls are found in oysters that live in the ocean. The three main kinds of saltwater pearls are Tahitian pearls, South Sea pearls and Akoya pearls. It is known as a popular and colorful gemstone.

One of the distinctive things about pearls is their naming convention. Instead of being named by the style of stone, pearls are commonly referred to by their physical measurement.

For example, an opera is a strand of pearls that reaches the breastbone. A collar sits against the throat area and does not hang down on the neck. A pearl choker is a similar style to the collar, but sits down on the neck more. A princess sits below the collarbone. A matinee of pearls hits just above the breastbone. A pearl rope is any strand that falls down farther than the opera length.

If you are unsure of which length you are looking for or the proper name for it, consult a jeweler who specializes in fine jewelry. They can help you find a style that best fits your personality.