There are three main pearl shapes: spherical, symmetrical, and baroque or non-symmetrical. The basic pearl shapes fall within those categories like this:
Spherical
กลม
Near-round
Symmetrical
Oval
Button
Drop
Teardrop
Baroque (Non-Symmetrical)
Semi-baroque
Baroque
Surface Markings
As a mollusk creates a pearl, the layers of nacre do not always adhere smoothly. Sometimes spots and bubbles, called surface markings, can appear in the layering process. Pearls with the smoothest surfaces are the highest-quality, and the most sought-after—and they come with a price tag to match.
Treatments
There are several gem treatments commonly used to enhance a pearl’s beauty. It safe to assume that every Akoya pearl has been bleached to remove dark spots and create a more uniform color. This treatment may also include irradiation and dyeing. Dye is used to create many different hues, particularly with freshwater species. Irradiation is another method used to change a pearl’s natural color.