We have two in stock. Giant clams, also known as Ōgikai (fan clams) or Shako, are the world's largest clams. They inhabit the shallow coral reefs of tropical to subtropical waters and are the largest species of bivalve. This includes the Tridacna gigas. They are named for their appearance, which resembles a fan. Giant clams are a rare organic gemstone, white like jade, and a Buddhist sacred object. They are one of the four major organic gemstones, along with pearls, coral, and amber. In Chinese Buddhism, they are revered as one of the seven treasures, along with gold, silver, lapis lazuli, agate, coral, and pearls. Giant clams are one of the seven treasures of Buddhism, and it is said that chanting the Nembutsu while using a giant clam rosary can bring twice the merit. They are said to calm the mind, be effective against insomnia, and are best worn for a long period. They are also said to heal mental fatigue, improve eyesight, and have the power to improve fortune, maintain health, and ward off evil.