Thank you for viewing. "Yakuo Stone" Raw Stone 2 pieces, in a case Yakuo Stone has been used as a "medicinal stone" in China for over 2000 years. It is a stone that was used in Tibet and China in ancient times for medical purposes. It is said to be effective for high blood pressure, neuralgia, stiff shoulders, and insomnia, even today. The effectiveness varies from person to person. This is not for medical use.