Glass Spherule (image) Geological Society of America Share Print E-Mail Caption This is a secondary electron image showing a glass spherule formed in high-voltage flashover experiments to examine the effect of ash contamination on electrical insulators. Photo by Kimberly Genareau. Credit Kimberly Genareau, Genareau et al., Geology, Geological Society of America. Usage Restrictions Credit Kimberly Genareau, Genareau et al., Geology, Geological Society of America. Share Print E-Mail 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.