Volcanic Glass (image) Smithsonian Caption Molten magma erupted onto the seafloor freezes to glass that contains clues to its origin in Earth's deep interior and ancient past (field of view ~1 cm). Volcanic glasses like this one may reveal a link between Earth's oxidation state and the deep carbon cycle. Credit Glenn Macpherson and Tim Gooding Usage Restrictions None 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.