Any pearl that is not round, oval, drop-shaped or button-shaped counts as baroque. The GIA sorts pearl shapes into three groups: spherical (round, near-round), symmetrical (oval, button, drop) and baroque (semi-baroque, baroque, circled with grooves). Within the baroque group, the spectrum runs from slightly distorted to freely grown sculptures.
Baroque shapes are the rule, not the exception. Among South Sea pearls, only 10 to 30 percent of a harvest is round or near-round; among Tahitian pearls it is under 10 percent, while baroque pearls there make up around 40 percent. Because roundness is rare, a baroque pearl of the same lustre and size often costs only a fraction of its round sister.
This is precisely what makes them attractive for jewellery: large South Sea baroque pearls of 15 mm and more would be almost unaffordable if round. The lustre often appears livelier because light refracts on curved surfaces. More on prices by shape in the article Pearl necklace: cost by pearl type.
