The aggregates of globular bodies seen in the section so greatly resemble the globulites of slags and natural glasses, and in their arrangement so forcibly recall the structures seen in the well known pitchstone of.    From Wordnik.com.  [Scientific American Supplement, No. 595, May 28, 1887] Reference

Sardara, Ploaghe, and other places; and considerable extents of trap and pitchstone are frequently met with on limestone strata, while others, tending fast to decomposition, are incorporated with an earth formed of comminuted lava.    From Wordnik.com.  [Rambles in the Islands of Corsica and Sardinia with Notices of their History, Antiquities, and Present Condition.] Reference

I strongly suspect the underlying granite has altered such beds into this pitchstone.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 1] Reference

The lavas are curious from abounding in, or rather being in parts composed of pitchstone.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 1] Reference

Mr. Knox, of Dublin, by converting some of the numerous pitchstone fragments that lie scattered about.    From Wordnik.com.  [The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland] Reference

We were stopped by a small circular wall of porphyritic lava, with a base of pitchstone, which concealed from us the view of the crater.    From Wordnik.com.  [Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 1] Reference

I had previously been exceedingly puzzled by meeting in the sandstone, thin layers (few inches to feet thick) of a brecciated pitchstone.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 1] Reference

We rowed southwards in our little boat, through the channel of Eilean Chaisteil, along the trap-rocks of the island, and landed under the two pitchstone veins of.    From Wordnik.com.  [The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland] Reference

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.    From Wordnik.com.  [Complete Story of the San Francisco Horror] Reference

Their flanks were blotched with a livid nitrous efflorescence, with flaring sulphur, unhealthy verdure of pitchstone, streaks of arsenical vermilion; their beds -- a frantic maze of boulders.    From Wordnik.com.  [South Wind] Reference

When the basis of the lavas of the Malpays changes from pitchstone to obsidian, its colour is paler, and is mixed with grey; in this case, the feldspar passes by imperceptible gradations from the common to the vitreous.    From Wordnik.com.  [Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 1] Reference

The property location relative to the nearby Rössing and Langer Heinrich uranium mines, and other uranium occurrences in the western Namibian uranium district, is illustrated on the company's website (www. pitchstone.net).    From Wordnik.com.  [Marketwire - Breaking News Releases]

This seems a curious fact, when we take into account the identity, in their mineral components, of the pumice and obsidian of the recent volcanoes; and that pitchstone, the obsidian of the trap-rocks, is resolvable into a pumice by the art of the chemist.    From Wordnik.com.  [The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland] Reference

The masses of pitchstone a-top, though so intensely black within, are weathered on the surface into almost a pure white; and we found lying detached among them, fragments of common amygdaloid and basalt, and minute slaty pieces of chalcedony that had formed apparently in fissures of the trap.    From Wordnik.com.  [The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland] Reference

There occur, intercalated with the columnar beds, a few bands of a buff-colored non-columnar trap, described by M'Culloch as of a texture intermediate between a greenstone and a basalt, and which, while the pitchstone around it seems nearly indestructible, has weathered so freely as to form horizontal grooves along the face of the rock, from two to five yards in depth.    From Wordnik.com.  [The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland] Reference

I even thought, with many other geologists, that obsidian, so far from being vitrified lava, belonged to rocks that were not volcanic; and that the fire, forcing its way through the basalts, the green-stone rocks, the phonolites, and the porphyries with bases of pitchstone and obsidian, the lavas and pumice-stone were no other than these same rocks altered by the action of the volcanoes.    From Wordnik.com.  [Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 1] Reference

Honorable George Knox, of Dublin, "says Mr. Robert Allan, in his valuable mineralogical work," that the pitchstone of Newry, on being exposed to a high temperature, loses its bitumen and water, and is converted into a light substance in every respect resembling pumice. ".    From Wordnik.com.  [The Cruise of the Betsey or, A Summer Ramble Among the Fossiliferous Deposits of the Hebrides. With Rambles of a Geologist or, Ten Thousand Miles Over the Fossiliferous Deposits of Scotland] Reference

CFO www. pitchstone.net.    From Wordnik.com.  [The Earth Times Online Newspaper] Reference

(see maps at www. pitchstone.net).    From Wordnik.com.  [Marketwire - Breaking News Releases] Reference