Gypsum Rocks (IMAGE) Johns Hopkins University Caption Researchers traveled to the Atacama Desert in northern Chile to collect samples of gypsum. The specimens were brought back to the US, and half-millimeter 'coupons' of material were used in lab experiments that ultimately confirmed the role microbes play in transforming the rock to an anhydrous phase through water extraction. Credit David Kisailus / UCI 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.