Japan occupies a particular place in the gem trade as both a producer of distinctive native materials and as one of the world's most discerning consumer markets. Though never a major source of coloured stones in the volumes seen from Burma, Sri Lanka or East Africa, the islands have contributed several materials of historic significance, and the postwar Japanese market has been pivotal in shaping global standards for fine pearls, white diamonds and high-clarity coloured stones.

Native Gem Materials

The most internationally recognised Japanese gem material is the Akoya cultured pearl, developed by Kokichi Mikimoto and his contemporaries in the early twentieth century. Cultured saltwater pearls from Pinctada fucata martensii bays around Mie, Ehime and Nagasaki Prefectures established the modern cultured pearl industry. Akoya pearls are typically 6 to 9 mm, with the bright neutral lustre and pale rose to silver-white body colour for which Japanese culturing techniques are known.

Japan also produces small quantities of native coloured stones. Translucent green and white nephrite jade was worked from the Itoigawa region of Niigata Prefecture from the Jōmon period onward, and Itoigawa jade was designated the National Stone of Japan by the Japan Association of Mineralogical Sciences in 2016. Pyrope-spessartine garnet, axinite, datolite and rare iron-rich tourmaline have been recorded from various small localities, and freshwater pearls were once cultured in Lake Biwa, though that production has now largely ceased on a commercial scale.

Trade and Market

From the late 1960s through the bubble era of the late 1980s, Japan was the single largest market for fine diamonds and coloured stones in absolute terms, driving demand for round-brilliant ideal-cut diamonds, top-grade Burmese ruby, Kashmir-style sapphire and unheated paraiba tourmaline. Japanese laboratories and trade bodies, particularly the Central Gem Laboratory in Tokyo, became influential globally for pearl and coloured stone testing.

The Japanese consumer market remains highly selective. Bridal demand favours D to F colour, IF to VVS clarity diamonds with hearts-and-arrows symmetry, and the country sustains specialist appetites for paraiba tourmaline, demantoid garnet, alexandrite and untreated padparadscha. The Tokyo trade is an important secondary market for Japonisme-influenced antique jewellery and twentieth-century Western signed pieces.

Trade Bodies and Shows

The principal industry organisation is the Japan Jewellery Association (JJA), which administers nomenclature and disclosure standards aligned to international norms. The International Jewellery Tokyo (IJT) fair, held annually since 1990, is the largest gem and jewellery trade show in Asia outside Hong Kong. JCK Tokyo and the Japan Jewellery Fair operate parallel trade events in Tokyo and Yokohama.