This is a very valuable Kizu-yama awasedo (natural sharpening stone). Kizu-yama is said to be comparable to Nakayama. The quarry is already closed, and due to the scarcity, prices seem to be soaring. It's relatively soft and easy to sharpen with, providing excellent usability. The grinding mud is very fine-grained, resulting in a hazy finish on the jigane (softer steel) and a glossy finish on the hagane (harder steel). The stone quality is superb. If the base is exposed, it's easy to sharpen the cutting edge of Japanese knives without unevenness, resulting in a beautiful finish with a clearly defined weld line. This is a versatile and highly recommended sharpening stone. Size: 207mm x 51.5mm x 26mm Preserved by Ishi-san (stone specialist)