Some time ago, I wrote about Ogatsu stone, which is found in Japan. It is a a dark grey stone, nearly black in color, easily carved and used for many purposes. Ogatsu stone is famous for suzuri as it is a dense stone with low porosity.
A characteristic of suzuri carved from Ogatsu stone is that the outer borders and edges of the stone often are left as natural as possible. The well is smooth, with an area for the making of sumi, and a deeper area to store the ink. Touching the surfaces smoothed for ink making, it is an incredible soft feeling, very smooth without any sense of roughness beneath the fingertips. Outside the well, the stone is smoothed, but the texture of the stone is allowed to come through. The sides are rough, as if chipped away with another stone, but then smoothed over, enough to preserve the ripples in the slate, but not to be unpleasant or rough to the touch.
This suzuri is in two parts, a lid, and a stone for grinding and storing ink. The lid is an extension of the stone from which the suzuri is carved, and simply rests on top of the the stone. The weight of the lid helps prevent it from moving off the stone, but, unlike the boxes of Chinese ink stones, this one can slide, and a small disaster could certainly result if it were to fall to the floor!
The length of the stone, including the lid, is about 7.25 inches (18.5 cm) and 5 inches (12.5 cm) at its widest. Total weight of lid and suzuri is about 2.5 lbs.
Every stone has its own characteristics. Japanese stone differs from Chinese, from what I can tell, in that it is less porous than Duan or She. It takes a bit more effort to make sumi with the Japanese stones I have, but not in a negative way – it is simply a different experience. Fine stones from both countries are definitely worthwhile purchases, as are professional grade sumi sticks.