pitchstone

pitch·stone

P0335100 (pĭch′stōn′)n. Any of various volcanic glasses distinguished by their dull pitchlike luster.

[Translation of German Pechstein.]

pitchstone

(ˈpɪtʃˌstəʊn) n (Geological Science) a dark glassy acid volcanic rock similar in composition to granite, usually intruded as dykes, sills, etc[C18: translation of German Pechstein]

Thesaurus

Noun

pitchstone - dark acid granitic glassvolcanic glass - a kind of natural glass produced when molten lava cools very rapidly

Pitchstone

pitchstone

[′pich‚stōn] (geology) A type of volcanic glass distinguished by a waxy, dull, resinous, pitchy luster. Also known as fluolite.

Pitchstone

a volcanic glass with a water content of up to 10 percent. Pitchstone is black, reddish, or light green and has a waxy, resinous luster. It contains microliths and, less frequently, phenocrysts. Distinctions are made between rhyolite, trachyte, diabase, and phonolite pitchstones. Upon heating pitchstone to high temperatures, gases are liberated with volumes 15–20 times greater than the volume of the original rock. Pitchstones are found in volcanic regions in France (Auvergne), Hungary, the German Democratic Republic (Saxony), and Great Britain (Scotland). Pitchstone is used in the production of “popped” (exploded) perlite.

pitchstone

pitch·stone

pitchstone

Pitchstone

pitchstone

Pitchstone

pitchstone

Words related to pitchstone

noun dark acid granitic glass

Related Words