Ancient Roman glass (IMAGE) Tufts University Caption Microscopic view of photonic crystals on the surface of ancient Roman glass Credit Giulia Guidetti Usage Restrictions Use permitted with credit to Giulia Guidetti License Original 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.