This is an inkstone used by my ancestors from the Meiji era to the early Showa era. It is believed to be a Chinese Ruixi inkstone, but it is not definitively confirmed to be Ruixi. It is housed in a case, possibly made of rosewood, that is shaped to fit the inkstone. It shows considerable signs of use, and the center of the inkstone shows some wear (approximately 0.5mm?). The dimensions, including the case, are: maximum width approximately 105mm, maximum length 144mm. Weight, including the case: approximately 560g.