Quality Factor One : Luster
Luster is the shine and glow of the pearl, and a vary important factor when it come to judging beauty .The intensity of a pearl's luster is determined by its nacre, the layers of calcium carbonate that make up the pearl. The longer a pearl is left in the oyster, the thicker the nacre. The luster of a good quality pearl should be bright and not dull. The degree of luster and orient is one of the most important factors in determining the quality and value of the pearl

 Quality Factor Two: Surface
Cleanliness refers to the absence of disfiguring spots, bumps or cracks on the surface of a pearl. The cleaner the surface of the pearl, the more valuable. This refers to the pearl's freedom from such surface blemishes as small blisters, pimples, spots, or cracks. Imperfections may also appear as desk spots, small indentations welts or blisters, or surface bumps. Think of the pearl's surface as you would your own skin. Just as our own is rarely completely free of little imperfections, so it is with the pearl.

Quality Factor Three: Shape
Pearls come in many shapes. Depending on how they are formed within the mollusk. Because most people expect pearls to be round, and round pearls are very rare, they tend to be much more expensive than other shapes. Shape in pearls :Round ,Semi Round , Drop, Button, Baroque, Semi-Baroque , Circle !­

Quality Factor Four: Color
Color is an important factor to consider for several reasons. Individuals have very personal preferences in terms of color based on their own skin, eye, and hair color and should select a color that is best suit to them. Color also affects cost because some are rarer than others. Cultured pearls come in a variety of colors from pink to black. While the color of a pearl is really a matter of the wearer's preference , usually rose or silver/white pearls tend to look best on fair skins while cream and gold toned pearls are flattering to darker complexions. In naturally "black" cultured pearls, the color range from light gray to dark gray, and also includes blue and green; in black pearls, a green overtone is the rarest and most costly, especially when it results in an intense "peacock" color. Cultured pearls are available in many natural colors - white, black, gold, pink, green, blue, gray !­ from many parts of the world.

Quality factor Five: Size
Cultured pearls are measured by their diameter in millimeters. They can be smaller than one millimeter in the case of tiny seed pearls, or as large as twenty millimeters for a big south sea pearl. The larger the pearl, other factors being equal, the more valuable it will be. The average sized Akoya pearl sold today is between 7and 7.5 millimeters. In South sea pearls an 8mm pearl is small , 12-15 mm is average , and over 16mm is very large.