What is a folgerite?

Answer 1

When lightning strikes sand it create what is called a folgerite

Answer 2

A fulgurite is a glassy tube formed when lightning strikes sandy soil or other silica-rich materials, such as rocks or beach sand. The intense heat from the lightning melts and fuses the silica particles together, creating a hollow tube-like structure. Fulgurites are often found in areas where lightning strikes frequently.