Review on Optical Spectrum Physics Teaching Novelty & Gag Toys by Mikey Jackson

My friend who actually has real crystal glass informed me that this prism is actually not solid but hollow. This information is further reinforced by the fact that there was some odd residue and smudges inside the prism when I received this thing. Of course I couldn't wash off a single stain because of this. Will never buy again and will warn my friends to stay away from this product and seller.