South Sea Pearls: Origin, Colors, Sizes and Value

South Sea cultured pearls are the largest cultured pearls.¹³ GIA attributes their value to their large size and thick nacre, the result of a long growth period, and to the limited conditions they need to grow.³

Where South Sea pearls come from#

South Sea pearls come from Pinctada maxima, the largest of the pearl oysters, known as the silver-lipped or gold-lipped pearl oyster.¹ White South Sea pearls come from the silver-lipped oyster and golden ones from the gold-lipped oyster. The silver-lipped shells are found mostly south of the equator, and the gold-lipped ones to the north.²

Before culturing, pearling fleets dived for this oyster’s large natural pearls and for its mother-of-pearl.¹ CIBJO defines a South Sea cultured pearl by the oyster, as one grown in P. maxima.¹ US guidance defines it by place instead: a South Sea pearl must come from a saltwater mollusk of the Pacific Ocean South Sea Islands, Australia or Southeast Asia.¹⁴

Where South Sea pearls are farmed#

South Sea pearls are cultured mainly in Australia, Indonesia, the Philippines and Myanmar.¹ CIBJO’s 2025 guide describes the main producing regions this way:⁶

• Australia: mostly wild, silver-lipped oysters caught by divers; pearls typically 11 to 16 mm; one pearl per oyster every 2 to 3 years; about 800,000 pearls a year, with a retail value of about US$300 million.⁶
• The Philippines: hatchery-bred, mostly gold-lipped oysters; pearls typically 9 to 16 mm, mostly champagne to gold; one pearl every 2 to 3 years; about 1 million pearls a year, worth about US$230 million at retail.⁶
• Indonesia, Myanmar and Vietnam: hatchery-bred silver- and gold-lipped oysters; pearls typically 8 to 13 mm, mostly cream to gold; one pearl every 1 to 2 years; about 3 million pearls a year, worth about US$230 million at retail.⁶

Wild oysters make up about 70% of Australia’s production, and some oysters are now bred in hatcheries to supplement and protect the wild stocks.⁶ In Western Australia, the regulator sets a yearly quota across three fishing zones for 14 licence holders, from 500,000 oysters to 1.5 million in a good year, and places observers on pearling vessels.¹¹

How South Sea pearls are grown#

In Western Australia, divers hand-pick wild oysters from the seabed in the Pilbara and Kimberley regions, with the main grounds near Broome, and the oysters are often seeded on board the pearling boats. Seeding means surgically inserting a shell bead, together with a piece of mantle from another oyster, into the oyster’s gonad.¹¹

The seeded oysters go back to the seabed in net panels, which are turned regularly for three months to help the pearls grow round. They then move to sheltered farm waters on floating lines, where crews regularly clean off parasites, because a stressed oyster can produce a blemished pearl.¹¹

Nacre first forms on the bead about 45 days after the operation, and it is secreted fastest in water of 25–30 °C.¹² GIA says P. maxima generally needs at least two years to grow its pearls,² and Western Australia’s fisheries department says it takes up to two years for the pearls to reach a desirable size and quality.¹¹ Across these sources, the dataset gives a growing time of 1–3 years (two to three years in Australia and the Philippines)⁶.

Good oysters can be seeded several times, each time with a larger bead, so each pearl is larger than the one before.¹¹ One oyster can produce up to four pearls this way.¹² In 1954, a joint venture began culturing pearls in Pinctada maxima at what is now Kuri Bay, Western Australia, where a method using larger beads let the farm harvest after only 18 months.¹⁵

South Sea sizes, shapes and colors#

South Sea cultured pearls are typically 9–16 mm, within a range of 8–18 mm⁶, and pearls over 20 mm are rare.⁶ GIA’s journal describes them as much larger than Akoya, routinely over 10 mm in diameter.¹⁵

CIBJO lists their shapes as round, oval, button, drop, circled and baroque⁶, and GIA says they are most often round, though any shape occurs.⁴

Their colors are white, silver, cream, champagne and golden⁶, with overtones of pink, blue and green.⁶ GIA notes that yellow ones are often called “golden” in the trade.⁴

Quality factors for South Sea pearls#

South Sea cultured pearls are judged on GIA’s seven value factors.¹⁶ Their nacre is their strength: it is the thickest of any bead-cultured pearl,² typically between 1.5 and 3.0 mm.¹⁰ In one X-ray image GIA published, an 11.15 mm South Sea pearl had about 1.92 mm of nacre, against 0.34 mm on a 6.85 mm Akoya.¹⁷

GIA notes that South Sea pearls often have a satiny luster.¹⁸ CIBJO says fine-quality Australian South Sea cultured pearls need no treatment, while lower qualities are given maeshori, a luster treatment.⁶ A GIA study of low-quality pearls found that processing to improve their surfaces could remove all the nacre, leaving only a coated bead.¹⁰

What affects the price of South Sea pearls#

GIA’s journal describes South Sea pearls as significantly more costly than Akoya.¹⁵ GIA attributes their value to their size, their thick nacre and the limited conditions they need to grow.³ Within South Sea pearls, the usual value factors set the price, and when other factors are equal, larger pearls are rarer and more valuable.¹⁸

Identification, treatments and imitations#

X-ray imaging shows the bead in a South Sea pearl and lets labs measure its nacre.¹⁷ It also helps separate bead-cultured, non-bead cultured and natural pearls from this oyster.²

Golden color can be natural, or produced by heat or dye. Labs separate natural from treated golden pearls with UV-visible spectroscopy, fluorescence and photoluminescence.^{8 9 19} South Sea pearls are generally not treated in their countries of origin beyond washing and polishing, though some Japanese pearl companies treat them.¹²

Pearls without a bead also come from this oyster. These non-bead cultured pearls, sold as keshi, can have internal structures much like those of natural pearls; the page keshi pearls explains them.²⁰

Caring for South Sea pearls#

South Sea cultured pearls need the same care as other pearls. Put them on after perfume and cosmetics,¹³ wipe them with a soft cloth dampened in clean water after wearing, and keep them away from acids, solvents, heat and ultrasonic cleaners.¹ The care section has the full routine.