American Pearl · Pearl Guide

A Brief History of Pearls: Size of South Sea Pearls

The short answer

South Sea pearls are among the largest cultured pearls, usually 8 to 22mm with an average of about 15mm. Smaller South Sea pearls, from 2 to 8mm, are usually baroque keshi pearls, which are solid nacre with no nucleus.

Reviewed by American Pearl’s pearl specialists · Updated October 2026

	A brief history of pearls		SIZE OF SOUTH SEA PEARLS South Sea pearls are among the largest of all saltwater cultured pearl varieties, ranging from 8 millimeters to as large as 22 millimeters. Their average size is 15 millimeters. Note that South Sea pearls are also found in smaller sizes, between 2 and 8 millimeters. Pearls of this size are usually very baroque "keshii" pearls, a very rare type of pearl that is all nacre with no nucleus. [kesh-ee]
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South Sea pearl sizes: common questions

How big are South Sea pearls?

South Sea pearls are usually 8 to 22mm, averaging about 15mm.

What are keshi pearls?

Keshi pearls (said “KESH-ee”) form by chance during culturing and are made entirely of nacre with no bead nucleus. South Sea keshi are usually baroque and 2 to 8mm.

What is the largest cultured pearl type?

South Sea pearls are the largest cultured pearl type, and can reach 20mm or more.