This is an empty 1/6 plate geometric with scallop countour thermoplastic case for a daguerreotype, ambrotype, or tintype. 

The reference number for the case is Berg3-60 and it is classified as a Very Rare case with less than 60 known examples. It measures about 3.75 x 4.25 inches. There is some some chips along two edges of the bottom half of the case (see listing photos 4 and 5) and there is some sort of flaw in the upper left corner of the top half of the case (see listing photo 1). The railings next to all the hinges are cracked (see listing photo 2).