As with all of the Arabian Gulf countries, Qatar's main commodity before it began exporting oil and natural gas to the world was pearls, the iridescent precious beads formed in oyster shells. For centuries, pearls have been used in jewellery and none were considered as fine as the natural ones found in the Gulf, according to author Michael Quentin Morton, who has written eight books on Middle East history, including <i>Masters of the Pearl: A History of Qatar</i>. Traders in Qatar worked to satisfy Europe’s demand, shipping the gems from local markets to Bombay and onward to Baghdad, London or Paris, Morton says. Pearl diving could be dangerous work, keeping fishermen at sea for months at a time as they risked decompression sickness or marine animal attacks. Divers would tie a stone weight to one foot and descend 14 metres, often clipping their nose to hold their breath underwater. Fisherman prised open and sorted the oysters back on the boat. Saad Ismail Al Jassim was one of them. Seventy years ago, he used to free dive 13m deep into the waters of the Arabian Gulf, combing the seabed for oysters in the hope of finding a cluster of pearls. Al Jassim, now 87, was among the last of the country’s professional pearl divers. “Our journey would take three to four months,” he said. “We [would] eat, drink, sleep only on the boat.” In the early 1900s, Japanese businessman Kokichi Mikimoto perfected a process to make cultured pearls by implanting an irritant into an oyster, which stimulates the secretion process that creates the hard stone in nature. By the Second World War, artificial pearls had taken over the market, at one 10th of the cost of natural pearls, according to Morton. By 1939, oil was discovered in the Dukhan field in western Qatar and a decade later the country began exporting petroleum. In 1997, now independent after being a British protectorate, Qatar started exporting natural gas. These milestones transformed the country from desert outpost to burgeoning cosmopolitan city. Today, a 335-metre yacht that serves as a floating hotel for thousands of football fans is docked by the shore where divers on wooden boats once left to hunt for pearls — emblematic of the stunning transformation World Cup host nation Qatar has experienced over the past century. Al Jassim runs a small pearl shop in Doha’s Souq Waqif. A large black-and-white portrait of him as a bodybuilder hangs on the wall. The natural pearls he began hunting for at 18, and that his father did before him, are rare today. “Now, nobody is selling the natural pearl,” Al Jassim said. “Those who have them are keeping it.” Visitors often ask Al Jassim about his pearling days, prompted perhaps by a sign on the shop entrance with the line “the old pearl diver” below his name. But he shrugs off the change he’s seen in Qatar in his life. “Any country will change over such a long time,” Al Jassim said. “Even yours.”