Mineral agate. French Pyrenees.
<a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a>
CC BY-SA 3.0
<a href="//commons.wikimedia.org/wiki/File:Agate_Fontasse_Perimorphose.jpg" title="File:Agate Fontasse Perimorphose.jpg">File:Agate_Fontasse_Perimorphose.jpg</a>