The quality order of dzi beads is: milky white, black, brown, red and light green. Among them, ivory dzi beads are of high quality, so black is good.

According to the "Sacrifice Sutra" found in Dunhuang, the corpse tuo suggested that people should separate their flesh and blood after death and give it to the corpse tuo Lin. This custom existed before the Han Dynasty and Sui Dynasty. This custom may lead Tibetans who believe in Buddhism to have the same purpose. Among Buddhist stories, there are also Buddhist stories, such as "The corpse king gave pigeons with his body", "Mahasa gave his life to feed tigers" and preached "Bodhisattva gave her life to give alms".