"One man's trash is another man's treasure".
Probably 3D Print supports, found in
the "PLA to recycle" box at the local fablab. It's made of a type of plastic that reflect the light in some strange but nice way.
I don't know much about. It may be the "Polychromatic Silk PLA Filament" or something.
Whatever... now, they are 3 pieces of crystals or mirrors that can be used as #DungeonScenery or tabletop scatter terrain.