This is an Arcopal Coquillage pattern black glass sea shell shaped platter. It is 13" wide. The platter has no chip or cracks, but it has utensil marks and wear areas where the finish is not glossy. I think it is a residue that can be mostly polished off based on what I tried in one spot. Arcopal is a division of JG Durand in France. The black glass is red if held to a strong light. It was made in the 1990s.