Fulgurite (IMAGE) University of South Florida Caption When lightning strikes the sand, it may generate a cylindrical tube of glass, called a fulgurite. This fulgurite has a diameter of approximately 1.2 centimeters. Credit Dr. Matthew Pasek/University of South Florida Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.