realgar

American  

[ree-al-ger, -gahr] / riˈæl gər, -gɑr /

noun

1. arsenic disulfide, As 2 S 2 , found in nature as an orange-red mineral and also produced artificially: used in pyrotechnics.

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realgar British  

/ rɪˈælɡə /

noun

1. a rare orange-red soft mineral consisting of arsenic sulphide in monoclinic crystalline form. It occurs in Utah and Romania and as a deposit from hot springs. It is an important ore of arsenic and is also used as a pigment. Formula: AsS

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Etymology

Origin of realgar

1350–1400; Middle English < Medieval Latin realger ≪ Arabic rahj al-ghār powder of the mine or cave

Example Sentences

I stuck my head inside a cabinet to get a close look at the rocks of the arsenic sulfides realgar and orpiment, blazes of flame orange locked within the crystals.

From The New Yorker • Aug. 27, 2018

It is very widely distributed, being sometimes found native, and sometimes combined, as AsS, realgar, As2S8, orpiment, and FeAsS, arsenopyrite.

From An Introduction to Chemical Science by Williams, Rufus Phillips

These are orpiment, realgar, acetic acid, artificial camphor, per-iodide of tin, and the chlorides of tin and arsenic.

From Experimental Researches in Electricity, Volume 1 by Faraday, Michael

The orange-red sulphides of arsenic, orpiment and realgar, are formed both as primary minerals of igneous source and as secondary products of weathering.

From The Economic Aspect of Geology by Leith, C. K. (Charles Kenneth)

There is also a flux which separates sulphur, orpiment and realgar from metalliferous ore.

From De Re Metallica, Translated from the First Latin Edition of 1556 by Agricola, Georgius