Reddit user walking along a beach on the Baltic Sea found a strange, translucent yellowish rock. Thinking it was a rare piece of sea glass or natural raw amber, he took a picture, put it in his pocket, and posted the image to a rock-identification forum. Within minutes, a chemist replied with a frantic warning. The user had not found amber; he had picked up a piece of highly degraded white phosphorus. During the Second World War, thousands of firebombs were dumped into the ocean. The phosphorus chunks occasionally wash up on the beach and look exactly like beautiful stones. The horrifying reality is that white phosphorus will spontaneously ignite at thousands of degrees the exact second it fully dries out in the air. The chemist told him to submerge it in a jar of water and call the bomb squad. The user followed the instructions, preventing the rock from catching fir3 and burning completely through his leg.