The outer surface of the shell is covered in irregular concentric growth lines and ridges that are marked by violet lines. The periostracum is thin and whitish with dark brown markings. There is a remarkable ridge near the umbo on the interior of the shell. The outer margin of the shell is crenulated, meaning that it has small, tooth-like projections. The color of the shell is dirty white to grey with pale brown streaks. The interior of the shell is bright white with a deep brown or purple large adductor muscle scar.