In the days before pearls became widely available, these natural gems had great value as a precious stone because of the difficulties involved in obtaining them. Pearl divers, some of whom still practice their ancient trade today, use highly developed breath control to grab oysters from ocean depths in the hopes of finding a pearl. Pearl diving has existed for thousands of years, but modern mass-production of cultured pearls has rendered it virtually obsolete.
Traditional pearl divers use free-diving techniques, usually without oxygen tanks or other scuba equipment, according to All About Gemstones. They fill their lungs with air and dive to a river bottom or ocean floor, gathering up as many oysters as their breath control will allow before retuning to the surface. Because relatively few oysters actually produce pearls naturally, the divers would have to collect almost a ton of oysters just to come away with three or four perfect specimens of these valuable gems.
Pearl divers descend to depths of 100 feet (30 metres) or more, making them vulnerable to a condition called Taravana syndrome. This form of gradual hyperventilation, as described in Skin Diver Online, occurs over the course of several dives from repeated breath holding. Early experiments with diving suits for pearl divers in the 1890s created additional dangers. According to Kari Pearls, heavy diving helmets sometimes flipped the divers upside down, suffocating them as the air rushed out of their diving suits.
The most famous pearl diving regions include the Persian Gulf, China, Japan, the South Sea and Tahiti. Persian divers maintained their ancient techniques until the discovery of oil in the Gulf in the 1930s put an end to pearl diving there, rejecting diving suits and other technological innovations as a matter of pride. Australia began using aboriginal pearl divers in the 1870s to establish its own reputation as a pearl producer.
Pearl diving’s history may extend all the way back to 3000 B.C., when the ancient Sumerians began supplying pearls and mother-of-pearl to the Egyptians. According to All About Gemstones, Persian divers would jump from boats while carrying heavy stones to speed their descent, wearing a primitive form of goggles and using clips to squeeze their nostrils shut. The Japanese tradition of "ama," or female pearl divers, began 2,000 years ago, based on the belief that women had larger lung capacities than men and could better withstand the cold underwater temperatures.
The rise of the cultured pearl spelt the beginning of the end for the pearl diving trade. In 1893, Kokichi Mikimoto found success in his attempts to produce cultured pearls, according to Pearl-Guide. This technology meant that divers no longer had to go through the slow, inefficient process of gathering oysters by hand. In 2006, the "Guardian" published a story about the last few ama still active in Japan, noting that the population of female pearl divers there had declined from 6,000 in the 1940s to a mere 70.