Product: Natural Finishing Whetstone for Razors Size: 11.2cm x 10.5cm, Thickness 1.42cm (maximum value, with measurement error) Weight: 382g Hardness: 8 on a 9-point scale Regarding Hardness: This assessment was made by grinding the soft iron of a Japanese kitchen knife. A small amount of black residue was observed, but it might have been due to the nagura residue. Color/Appearance: A color like a dead tree. It's a borderline case, unsure whether to describe it as bright or dark. Due to the high amount of quartz and its hardness, a slight luster can be felt. Usability: A hard-grained type, similar to Narutaki. It can polish metal to a mirror finish, but when viewed at an angle, there are many shallow, fine scratches. It's too hard, so streaks are not a problem. Draw is strong, and if an unskilled person sharpens a plane, etc., there will be a vibration. It's not a difficult stone for razors and doesn't wear down. If you want to sharpen, a nagura is essential. However, like Arkansas stones, it seems to be used not for sharpening, but for refining the blade, like a strop. Comments: I think this stone was used in old barber shops. It's not a high-end item used for decoration, but rather a talisman-like stone that a master would give to his apprentice. Softer stones are easier to use, and in fact, the popularity was concentrated on the softer types. However, hard stones don't wear down, and if you have an inexpensive nagura, you can sharpen razors. And even if you're not skilled, using a hard stone at the end gives you some peace of mind. Honestly: I'm selling razors, so I'm also selling whetstones, but I've priced them quite high. Unlike razors that require maintenance, I'm only checking the quality of natural finishing whetstones. Also, I've bought over a dozen natural finishing whetstones so far, and I haven't found any with quality problems that prevent them from sharpening razors. Using a strop for finishing makes all stones the same. The stone looks beautiful when a strong light is shone on it. The actual item is often plain.