Maruo Kuro Renge Shiro Suita

Size (mm) / Weight

162x47x55 / 1,056g

Performance

Hardness / Fineness: 4- / 4+

While still technically from the same layer as traditional Maruo shiro suita, kuro renge suita are both finer and harder than their standard brethren. While not quite in the range suitable for finishing razors or tools, they offer a more refined polish and edge. This stone offers exceptional feedback and feel en route to a toothy, yet highly refined edge. Though it qualifies as a koppa, this stone is excellently sized for razors and is suitably sized for sharpening of larger blades and even polishing large kitchen knives. 

Aesthetics & Other Notes

This stone shows dense kuro (black) renge throughout the top 35mm and then appears to transition to more traditional Maruo shiro to finish. Unusually, in my experience, there is a thin layer of kawa on the bottom side.

This stone is lightly sealed from the wholesaler and remains fully stamped. 

Maruo (丸尾山, Maruoyama)

One of the few that continues to be operational, this Western mine is renowned for its soft shiro suita. This mine is also well regarded for its shiki uchigumori (tenjyou suita), ao suita, and aisa-layer stones. Once widely available and relatively cheap, increased demand has outpaced supply making these stones harder to get and more expensive than just a few years ago. All things considered, however, they are comparatively still quite attainable.