Pearl Day

What Is Pearl Day?

Every July 11th is "Pearl Day" (真珠記念日, Shinju Kinenbi) in Japan. On July 11, 1893, Mikimoto Kōkichi (御木本幸吉, 1858–1954) succeeded in culturing the world's first pearl at Ago Bay (英虞湾, Ago-wan) in Mie Prefecture — demonstrating for the first time that round, lustrous pearls could be grown by human intervention in oysters, rather than found by chance in wild oysters. Mikimoto's achievement revolutionized the pearl industry globally, making cultured pearls accessible to the general public and establishing Japan as the world's pearl capital.

Mikimoto Kōkichi and Cultured Pearls

Mikimoto Kōkichi was the son of a noodle shop owner in Toba, Mie Prefecture, who became fascinated by the pearl diving (海女, ama) culture of the Ise-Shima region and determined to find a way to grow pearls artificially. Working with marine biologist Yoshikichi Mizukuri, he experimented for years with inserting nucleus material into Akoya oysters (アコヤ貝, Pinctada fucata) to stimulate pearl formation. After numerous failures, his July 1893 success produced a hemispherical cultured pearl — not yet the perfect round pearl he sought, but proof that the concept worked. A round cultured pearl followed in 1905.

The Global Pearl Industry

Mikimoto's achievement democratized pearls — previously rare and extraordinarily expensive treasures obtained from wild oyster beds — by making them cultivatable in commercial quantities. Mikimoto pearls and the broader Japanese cultured pearl industry transformed the global jewelry market, making pearl necklaces and earrings accessible to middle-class consumers rather than only royalty and the very wealthy. Japan's Akoya cultured pearl remains the international standard for round cultured pearls, while Japan also produces freshwater, South Sea, and Tahitian cultured pearls.

Mikimoto's Legacy

Mikimoto Kōkichi lived to age 96, continuing to oversee his pearl empire until shortly before his death in 1954. The Mikimoto Pearl Island (ミキモト真珠島) in Toba City, Mie Prefecture — where the original cultured pearl breakthrough occurred — is now a museum and tourist attraction celebrating the achievement that made Japan synonymous with pearl quality worldwide.

Fun Facts

• Ama divers: The female pearl divers (海女, ama) who traditionally harvested wild oysters from Japan's seas are still active in Ise-Shima, diving without equipment in the ancient tradition — now primarily for tourism demonstration rather than commercial harvest, as cultured pearl production has replaced wild diving.
• Mikimoto's quote: Mikimoto famously said he wanted to "adorn the necks of all women in the world with pearls" — a democratic aspiration that his cultured pearl technology made surprisingly close to achievable.