Phra Ajahn Sao Kantasilo Mahathera (1861-1941) was a monk in the Thai Forest Tradition of Theravadin Buddhism. He was a highly revered member of Dhammayuttika Nikaya, the order to which the Supreme Patriarch of Thailand, Somdet Phra Nyanasamvara Suvaddhana, also belongs. Ajahn Mun Bhuridatta Mahathera was one of his most well-known students.
After his cremation, his bone fragments were distributed to people and around the Thai provinces. And according to his followers, they transformed into crystal-like relics (Pali: Sarira-Dhatu) in various hues.