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.
If pumice was to be found anywhere in Scotland, we might a priori expect to find it in connection with by far the largest mass of pitchstone in the kingdom.
Mr. Knox, of Dublin, by converting some of the numerous pitchstone fragments that lie scattered about, "into a light substance in every respect resembling pumice.
And she mighty near rolled off down into Pitchstone Canyon, comin' up by the cut-off trail.
But the thought of Willomene lying in Pitchstone Canyon had kept sleep from me through that whole night, nor did I wish to attend Hank's burial.
I did see a figure, the figure I had looked at through the glasses, leaning strangely over the edge of Pitchstone Canyon, as if indeed he was peering to watch what might be in the bottom.
But there ain't no crawlin' out o' Pitchstone Canyon, they say.
The walls, or banks, of the channel have been denuded away, thus converting the pitchstone casting into a projecting wall of rock.
The trachytes occupy a position between the pitchstone lavas on the one hand, and the andesites and granophyres on the other.
Cartilaginous, or Cartilagineous, firm and tough in texture, like cartilage.
Formerly, when the orders themselves were not clearly made out, an artificial classification was required to lead the student down to the genus.
In one stream-bed in the swamps is exposed in situ a remarkable chocolate-coloured rock that looks like a greasy pitchstone or a palagonite-rock.
The pitchstoneor vitreous form of these trachytes is displayed in the blocks of an agglomerate-tuff between Tawaki and Mount Thuku.
Thus there are exposed on the lower slopes, tuffs and agglomerates of a basic pitchstone formed of a brown glass containing a few felspar and pyroxene microliths.
They comprise the coarse textured dolerite as well as the vitreous pitchstone and include both scoriaceous and amygdaloidal rocks.
In some localities, as on the south-west slopes of the Korotini Range, rocks of the basic pitchstone kind are predominant.
Footnote 129: In this connection see the description of the Soloa-levu pitchstone on p.
I followed it along in a north-west direction, gradually ascending on the way, and in time the rubbly pitchstone gave place to a hardened palagonitic clay rock, which was observed as high as 2,300 feet.
At its foot near the river there is exposed at the roadside a rubbly pitchstone formed of a basic glass, inclosing porphyritic crystals of plagioclase, augite, and olivine, which is described on page 313.
Near the mouth of the Narengali valley (see page 149) I found what appears to be a palagonite-tuff overlain by agglomerates formed of tachylytic pitchstone and of semi-vitreous amygdaloidal basalts.
Since our first acquaintance, that memorable summer of Pitchstone Canyon when he had taken such good care of me and such bad care of himself, I had learned pretty well about horses and camp craft in general.
McLean drifted to Green River last year and went up over on to Snake, and up Snake, and was around with a prospecting outfit on Galena Creek by Pitchstone Canyon.
Thence they passed north over Pitchstone Plateau until they struck the valley of Moose Creek.
I had never seen him look as he did now, not even in Pitchstone Canyon when we came upon the bodies of Hank and his wife.
And the expedition ended in an untravelled corner of the Yellowstone Park, near Pitchstone Canyon, where he and young Lin McLean and others were witnesses of a sad and terrible drama that has been elsewhere chronicled.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "pitchstone" in a variety of sentences. We hope that you will now be able to make sentences using this word.
