The Collaborative International Dictionary of English v.0.48:

Libethenite \Li*beth"en*ite\ (l[i^]*b[e^]th"[e^]n*[imac]t), n.
   [From Libethen, in Hungary, where it was first found.] (Min.)
   A mineral of an olive-green color, commonly in orthorhombic
   crystals. It is a hydrous phosphate of copper.
   [1913 Webster]