unknown sedimentary rock 7

Description

This particles in this rock are fine and can't be seen by the naked eye. The rock feels very smooth to the touch and sharp in some places. This rock doesn’t taste salty. This rock doesn't fizz with a drop of acid. MSU GGP CC BY(4.0) via sketchfab [https://creativecommons.org/licenses/by/4.0/legalcode]