The whole northern and lower portion of the island had vanished, except an isolated pitchstone rock, ten yards square, and projecting out of the ocean with deep water all around it.
"Complete Story of the San Francisco Horror"
Richard Linthicum Trumbull White Samuel Fallows
If the base be greenstone, basalt, or pitchstone, the rock may be denominated greenstone-porphyry, pitchstone-porphyry, and so forth.
"The Student's Elements of Geology"
Sir Charles Lyell
Ponza Islands, globiform pitchstone of.
"The Student's Elements of Geology"
Sir Charles Lyell