pitchstone

American  

[pich-stohn] / ˈpɪtʃˌstoʊn /

noun

1. a glassy volcanic rock having a resinous luster and resembling hardened pitch.

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pitchstone British  

/ ˈpɪtʃˌstəʊn /

noun

1. a dark glassy acid volcanic rock similar in composition to granite, usually intruded as dykes, sills, etc

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Etymology

Origin of pitchstone

1775–85; translation of German Pechstein. See pitch ², stone

Example Sentences

Such media are the volcanic rocks when they are rapidly cooled, producing various kinds of pitchstone, obsidian, &c.

From Project Gutenberg

There are numerous varieties of lava, such as basalt, obsidian, pitchstone, pearlstone, trachyte, &c.; some are heavy compact rocks, others are light and porous.

From Project Gutenberg

The walls, or banks, of the channel have been denuded away, thus converting the pitchstone casting into a projecting wall of rock.

From Project Gutenberg

The lavas comprise dark pitchstone, resembling that at Kirk Yetholm, and porphyritic and amygdaloidal andesites and basalts.

From Project Gutenberg

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.

From Project Gutenberg