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

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Example Sentences

See Examples For:

pitchstone

Using four 20-in. mirrors, he focuses sunlight on powdered pitchstone in a glass laboratory tube until its water of crystallization steams off.

From Time Magazine Archive

In the south of the island there are sills and dykes of felsite, quartz-porphyry, rhyolite, trachyte and pitchstone.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 6 "Armour Plates" to "Arundel, Earls of" by Various

There is also much imperfect rubbly pitchstone, with the interstices charged with powdery carbonate of lime apparently of contemporaneous origin.

From Geological Observations on South America by Charles Darwin

The characteristic rock is a black vitreous trachyte resembling pitchstone, but anhydrous.

From The Andes and the Amazon Across the Continent of South America by James Orton

I have much difficulty in believing that this thin layer of pitchstone flowed as lava.

From Geological Observations on South America by Charles Darwin

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