Unlike diamonds, there is no industry-wide standard for grading pearls, but six of their characteristics are typically considered when evaluating their quality and value: size, color, shape, surface, nacre and lustre.

Pearls are the only type of gemstone to grow inside a living creature. They form naturally within the soft inner surfaces of mollusks (mostly oysters, clams and mussels), and are generally considered of exceptional beauty and value. Most of the pearls found on the market today are cultured pearls, which are aided in their growth by the deliberate placement of an irritant inside the shell of a mollusk. When the mollusk produces layers of calcium carbonate to protect itself from the irritant, a pearl is usually formed. Cultured pearls are different to synthetic pearls, which are fully man-made and entirely fake. Cultured pearls are still natural gemstones that are simply assisted in their creation. Different types of mollusks produce pearls of varying sizes, shapes and colours. While non-cultured pearls that have been formed spontaneously in nature do exist, they are very rare.

While good-quality pearls are fairly strong and robust, they are still the most fragile of all the organic gemstones, and can scratch, crack and lose their shininess. Substances that pearls can become commonly exposed to, such as skin oils, sweat, creams, lotions and cleaning agents can strip away their natural sheen and cause them to dull.

Opulent and feminine pearl cocktail rings are forever in demand; however, pearl engagement rings and pearl wedding bands are becoming increasingly popular with those seeking to break away from tradition. The softness and pliancy of pearls allows them to be utilised within a variety of ring styles and shapes.

Pearl pendants are tasteful and classy accessories, and usually feature one or more pearls glued or drilled into a delicate setting and hung from a strand of precious metal. Because pearls are so soft and malleable, they can be incorporated into almost any design of pearl pendant.

The perfect complement to pearl necklaces and pendants, pearl bracelets make a beautiful addition to all flavours of outfits. The adaptability and flexibility of pearls have inspired a wide variety of elegant pearl bracelet designs. Given the simplicity of pearls themselves, much of the decorative elements found in pearl bracelets lie in the design of their clasps, which can range from the sleek and unembellished to the highly ornate.

If asked to imagine pearl jewellery, many people would envision a sophisticated string of spherical pearls draped elegantly around a woman's neck. A graceful accessory made famous by actress Audrey Hepburn, pearl necklaces are the most popular style of pearl jewellery, and come in a variety of designs.