Obsidian (Tokachi Stone) is a black glass formed when highly viscous magma cools rapidly after being ejected from a volcano. Its gemstone name is obsidian. Tokachi Stone is believed to have the power to discern the essence of things, foresee the future, and protect its owner. Origin: Tokachi, Hokkaido. It is a rare stone found in only a few places in Japan. Total weight: Approximately 2kg As it is a natural stone, there may be cracks, chips, and stains.