Pearl Diving in the Gulf: Why Bahrain's Natural Pearl Vanished

For centuries, almost every pearl necklace of note in Europe and India came from the waters between Bahrain, Qatar and the coast of the present-day Emirates. The trade is documented since antiquity, and its peak fell between 1900 and 1925. Then, within a single generation, an entire island economy collapsed, and Bahrain responded with a law that still stands: cultured pearls may not be traded there.

Why Gulf pearls were considered the finest

The pearl of the Persian Gulf comes from the oyster Pinctada radiata, a small pearl oyster that lives on the shallow banks north and east of Bahrain. The water there is warm and rich in salt, and it is fed by freshwater springs on the seabed. For centuries this mixture has been credited with the particular lustre of the pearls: a creamy white base colour with a faint hint of pink, and dense, even nacre. Gulf pearls are mostly small; large specimens were the exception and priced accordingly.

How rare size is can be seen in a case from the laboratory of the GIA, the Gemological Institute of America: in 2025 it examined three hollow natural pearls from Bahrain, the largest of which measured 16.00 × 13.94 × 11.60 millimetres yet weighed only 6.13 carats. Hollow pieces of this kind also turn up in antique jewellery from before 1900. The difference from a cultured pearl with its inserted bead nucleus is plain on an X-ray; there is more on this under natural or cultured pearl.

A trade older than any script

The oldest drilled pearls in the region were found by archaeologists at coastal settlements of the Gulf, dated to around 5,000 BC. According to the Pearling Path World Heritage Site, the oyster beds off Bahrain were fished from the 3rd century BC at the latest. UNESCO describes the island's pearl economy as a culture that lasted from the 2nd century into the early 20th century. Bahrain, known in antiquity as Dilmun, served as the trading hub between Mesopotamia, India and later Rome.

The rise to become the world power of the pearl came with the 19th century. In 1865 a British observer counted 1,500 pearling boats off Bahrain alone. In 1877 pearls made up three quarters of all the island's exports. Demand came from the princely courts of India, from Paris and from the United States.

The peak around 1900 in figures

The most precise figures come from John Gordon Lorimer, a British colonial official whose Gazetteer of the Persian Gulf of 1908 and 1915 surveyed the entire region. For 1905 he records 917 boats and more than 17,500 men sailing from Bahrain to the pearl banks. The value of pearl exports from the whole Gulf rose from 625,933 British pounds in 1873/74 to 1,076,793 pounds in 1904/05. Around 97.3 per cent of that turnover passed through the merchants of Manama and Muharraq.

After that the curve climbed even more steeply. Between 1900 and 1912 the value of Bahrain's pearl exports increased sixfold, and the 1911/12 season is regarded as the record year. For 1913 the proceeds of the Bahrain season are put at around 9 million US dollars. For context: Jacques Cartier travelled to Bahrain himself in 1912 to buy natural pearls directly from the merchants. The necklace of 128 natural pearls that Cartier exchanged in 1917 for a mansion on Fifth Avenue was worth 1 million dollars at the time. When its owner died in 1956, it was valued at just 151,000 dollars; the cultured pearl had changed the market in the meantime.

What a season at sea looked like

The great diving season, Al Ghus Al Kabir in Arabic, lasted around four months from June to September. During that time the boats stayed out on the banks and the crew lived on board. A diver wore a nose clip made of horn, tied a stone to his foot and let himself be pulled down to the seabed on a rope. His partner on board, the seib, hauled him back up on the rope; hardly anyone could last longer than four minutes. Whoever opened 1,000 oysters found, by the estimate of the historian Robert Carter, one pearl per 50 shells on average, so 20 pearls, and very few of those were round and flawless.

In the 1920s, according to the trade service Rapaport, more than a third of Bahrain's population depended directly on the pearl. Charles Belgrave, adviser to the ruler from 1926, summed up the situation in 1928 in a single sentence.

The prosperity and almost the existence of Bahrain depend on the pearl industry.

Charles Belgrave, 1928, quoted by the Qatar Digital Library

Three blows in twenty years

The first blow came from Japan. Kokichi Mikimoto had presented the first hemispherical cultured pearl in 1893, and from 1916 round cultured pearls were produced in series, as described in the article Mikimoto: how the first cultured pearl came about in 1893. As soon as these pearls reached Europe in the 1920s, prices for small natural pearls fell, because the eye could barely tell the two apart. Bahrain responded in 1928 with a public proclamation: the sale, offering and possession of cultured pearls for commercial purposes were banned. The ban remains in force; private individuals may merely own cultured pearls.

The second blow was the stock market crash of 1929. The buyers in New York and Paris stayed away, and the princes of India tightened their belts. The third blow came on 2 June 1932, when the first oil on the Arabian side of the Gulf shot out of the ground at Jebel Al Dukhan at 400 barrels an hour. The Bahrain Petroleum Company, by its own account, became a reliable employer for Bahrainis affected by the end of the pearl trade; in 1936 the refinery was running at 10,000 barrels a day. Oil work was year-round, pearl diving was seasonal and mostly financed on credit. According to Rapaport, income from pearls fell by around 70 per cent.

Bahrain's population fell from around 100,000 to 90,000 between 1908 and 1941 as diving families moved away. In 1947/48 India, the most important buyer, blocked the import of pearls. By around 1950, according to the Qatar Digital Library, the traditional fishery had all but disappeared.

What remains of the pearl economy

In June 2012 UNESCO inscribed the site Pearling, Testimony of an Island Economy on the World Heritage List. It comprises 17 buildings in the old town of Muharraq, three oyster beds in the sea named Hayr Shtayyah, Hayr Bu Amamah and Hayr Bu-l-Thamah, a stretch of coast at the southern tip of the island and the fort Qal'at Bu Mahir, from which the boats once set sail. The core zone covers 35,086 hectares, the buffer zone 95,876 hectares. UNESCO calls the site the only complete testimony to a pearling culture from the time before the cultured pearl.

The ban of 1928 had a side effect: Bahrain needed a laboratory that could separate natural pearls from cultured ones beyond doubt. In 1990 the Pearl and Gem Testing Laboratory was created by decree within the Ministry of Commerce, and in 2017 it was absorbed into the Bahrain Institute for Pearls and Gemstones, DANAT for short. According to Rapaport, the institute tests over 3 million pearls a year using X-ray and spectroscopy. Anyone who owns an inherited necklace of Gulf pearls will find the routes to an appraisal under inherited pearls: how to have them valued.

The return of the divers

Since 2017 Bahrain has once again been issuing diving licences for the pearl banks. Rapaport cites around 3,000 licensed divers, and in 2025 the UN reported more than 1,000 who are regularly active. They now dive with compressed air and stay underwater for an hour instead of four minutes. The yield remains tiny: about 7 kilograms of natural pearls come out of Bahraini waters each year, and worldwide, according to Rapaport, natural pearls make up just 0.2 per cent of the pearl supply. That is precisely where their value lies.

What the end of the Gulf pearl means for buyers now

Practically every natural pearl necklace that appears at auction was fished before 1930. New supply arrives in grams, not tonnes. Anyone buying natural pearls looks for three things: a laboratory certificate with X-ray evidence, the oyster species Pinctada radiata named, and a description of provenance that fits the era before the cultured pearl. In 1928 Bahrain decided never to mix natural and cultured pearls. The market would do well to follow suit.