Columbretes

“One particular variety of trachyte—which in some places resembles the piperine lava found near Naples—is represented by the heavy grey-black basaltic rocks found on the islet of El Bauzá and on various parts of La Ferrera.

In these areas, we find fragments belonging to a class of trachyte that is particularly dark and rich in amphiboles—as is not often seen—included in a light-grey Ponzá-style trachyte.”

Urios, G., Nachtwey, J., Translation, Columbretes, 1895, Castellón City Council, 1990.