Saphire grain (IMAGE) Heidelberg University Caption A sapphire from sediment in the Kyll, a river in the western Eifel. The crystal measures approximately 0.9 mm in diameter. Credit Sebastian Schmidt Usage Restrictions This image may be used only in connection with the contents of this press release, and the source of the image must also be cited. 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.