Chequ is a kind of deep-sea shellfish, which is distributed in tropical marine waters all over the world. Species are slightly different, often one or two meters in size. Shells are large and thick, hard and delicate, and can be regarded as semi-precious stones.
Cuckoo is one of the seven treasures of Buddhism. In the past, deep sea fishing was not easy, with few clams and good material characteristics, and was regarded as a treasure. Now the value of cockroaches is much lower and the price is more close to the people. It is a very good jewelry material.