This is a rectangular suzuri (inkstone). It has a slightly brownish color. I purchased it about 14 years ago at Kyukyodo in Kyoto for around 5000 yen and used it a few times. It came in a luxurious box, but I've lost it. There is a very small chip as shown in the third image. Other than that, there are small, silver-colored spots, and something silver- or white-colored on the back, but otherwise it's in good condition. There is some ink residue on the surface, but it is in a usable condition.