High quality Bian stones are limited. This is sourced from Shandong, China, the only place in the world that produces Bian stone. YINA Gua Sha is produced by a certified facility that creates medical grade Bian tools.
Bian stones come in a range of colors from brown to grayish black. The highest grade of Bian stones are Xuan Huang 玄黄 - rich brown with copper undertones. These are the stones in our current batch.
No two stones are completely alike. Stones with naturally- formed yellow spots are considered more rare and valuable.