This is an Egyptian mummy case, of the type that is probably painted gessoed wood. (It may be cartonage—I'm not terrific with technical terms in Italian, and didn't make many notes—plus the place was overrun with school kids that were a bit distracting....) It is the case of a woman, and we see the portion that presents her face and chest.

Below is a mosaic-glass fragment, representing an elaborate broad collar. This may have been made for a statue or figure, and not for a mummy. Oddly, the piece is shown upside-down. Remember, mosaic-glasses should not be confused with glass mosaics.

In the previous group of posts, I showed lots of examples of glass mosaics. In this art, small glass tesserae ("tess-er-eye"—usually square) are arranged together, and set in something like grout that holds it all together. In mosaic-glass, small (usually long) glass elements are arranged together, fused to become a single piece of glass, and then pulled ("drawn") to become miniaturized. The two approaches have in-common the possibility of creating recognizable shapes or abstract (geometrical, etc.) designs in glass. But the former is generally a large-scale and one-of-a-kind effort, whereas the latter is a miniature art that facilitates many similar reproductions of the design (buy removing slices from the resulting cane).