Moon Rock (IMAGE) Washington University in St. Louis Caption Cross-polarized transmitted-light image of a lunar rock reveals its hidden beauty. In broad daylight the rocks are an unprepossessing -- even an ugly -- gray. Credit J. Day Usage Restrictions please credit 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.