Almost fifty years ago, when Haraldur Sigurdsson first came to the University of Rhode Island from Iceland, he got interested in what makes some clam shells more purple than others.

Just as many-faceted as the birthstones themselves, though, are the origins of their names. A great many of them came into ...

In the depths of the San Lázaro rock-shelter in Segovia, Central Spain, archaeologists from the Complutense University of ...

Popular Michigan agate hunting locations include Whitefish Point, Grand Marais Beach, and Agate Beach. Known for their ...

With a little guidance and a lot of practice, even you can make stone tools the way our oldest ancestors did – and learn to recognize the signs of a deliberately made tool.