What is Bonfire beach glass? Glass that was thrown into a Bonfire on the beach, then mother nature swept it away into the water, sending her back to the beach after smoothing the glass with her powerful tumbles in the waves and sand. Seriously one of the most interesting pieces I’ve seen in 25 years, making it even better, my mom found this “treasure”! If you look closely, you can see some fossil imprints, which makes it even more interesting! This piece is 1″ long and 3/4″ wide.