天珠的藏語發音為『思怡』(DZI)，為美好、威德、財富之意，天珠，九眼石葉岩，屬於沉積岩之一種，含有玉質及瑪瑙成份，是一種稀有寶石。相傳天珠原屬於“天神”的寶物，因為出現了缺陷，被貶降到人間，後被藏族發現，所以西藏人至今仍認為天珠是“天降之石”。為藏密七寶之一。流傳下來的極其罕見。

The "Tianzhu Tibetan pronunciation Siyi" (DZI), for beauty, reputation, wealth of Italy, Tianzhu, nine eye stone shale belong to sedimentary rocks of jade and agate, containing ingredients, is a rare gem. According to legend, Tianzhu belonged to the "gods" treasures, because of the emergence of the defect, was demoted down to earth, after being found in Tibetan, so Tibetans still think is "Heaven stone beads". As one of the seven treasures of Tibetan buddhism. Extremely rare handed down.