Stone tool glued into a handle (IMAGE) New York University Caption The stone tool was glued into a handle made of liquid bitumen with the addition of 55 percent ochre. It is no longer sticky and can be handled easily. Credit Photo by Patrick Schmidt Usage Restrictions Use with this study only 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.