When buying gold South Sea pearls, be sure to ask if the color is natural. A high percentage of them are dyed and/or irradiated, especially those with strong gold or grayish-gold colors. If the color is natural, have this written on the sales receipt. It's advisable, too, to have expensive pearls checked by a gem laboratory.

SHAPE: The more round the pearl the more valuable it

is. But round South Sea pearls are very rare, far more rare than Akoya pearls, which are smaller and have thinner nacre. The thicker nacre and longer growth periods of South Sea pearls leads to a wide variety of shapes. These cannot be described adequately with just the four Akoya shape categories of round, off-round, semi-baroque and baroque. Some of the most common terms used to describe South Sea pearl shape are as follows:

Round: So symmetrical that the pearl will roll in a straight line on a flat inclined surface. Normally the most expensive shape.

Semi-round or off-round: Almost round, but the pearl will wobble or deviate to one side as you roll it.

Oval: An elongated round shape. It sells for much less than rounds.

Drop: Rounded at one end and elongated or pointed at the opposite end. The extension or tail corresponds to the incision where the nucleus was inserted. There are several variations of the drop shape. The drop shape is sometimes described as semi-baroque, especially if it's unsymmetrical. The more symmetrical a drop shape is, the greater its value. Very symmetrical drops with a smooth top and pleasing shape are called "perfect drops" or "knock-out drops" by some dealers.

Pear: A drop shape with a slightly concave "waist. " Some people use the terms "drop" and "pear" interchangeably.

Button: Rounded on one side and flatter on the other. The width is greater than the height. Buttons generally sell for less than drops and rounded shapes except in sizes over 16 mm where they are used for earrings. A round pearl of 17 mm sticks out too far from the ear, while a button makes an ideal earring. Since there's a high demand for buttons over 16 mm, their prices are high.

Acorn: Resembles an acorn. Has a high dome shape and flat bottom. This shape is practical for earring drops and brooches, but there is less demand for it than for the button shape.

Triangle: Has a pointed or drop-shaped top and a flat bottom. Short triangles may be used for stud type earrings, and long triangles can be used for pendants and dangling earrings.

Circle or circled: Have one or more parallel, ring-like furrows around the pearl. These circular formations do not occur as frequently in white and yellow South Sea pearls as in those which are dark-colored. Circled shapes sell for much less than the previous shapes. Circles or rims can be present on drops, ovals, off-rounds, triangles and buttons.

Baroque: Irregular or freeform. This shape is often preferred by designers because of its uniqueness. Generally, the baroque and circled pearls are the lowest priced of all the shapes. No matter what their shape, South Sea pearls are generally sold undrilled if they are not on a strand. This allows the buyer to determine how the pearls will be used or mounted. Be willing to compromise on shape. This may be necessary due to the high price and limited availability of round South Sea pearls.

SURFACE PERFECTION: South Sea pearls are graded for imperfections in the same way