The Collaborative International Dictionary of English v.0.48:

Peperine \Pep"e*rine\, Peperino \Pep`e*ri"no\, n. [It. peperino,
   L. piper pepper. So called on account of its color.] (Geol.)
   A volcanic rock, formed by the cementing together of sand,
   scoria, cinders, etc.
   [1913 Webster]