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

Both realgar and orpiment were important for pigments, medicinal purposes, and poisons among the Ancients.

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

Mix together realgar and orpiment; some object to this mixture on account of the poisonous nature of the ingredients.

From Young's Demonstrative Translation of Scientific Secrets by Young, Daniel

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

There are three known compounds of arsenic and sulphur, namely, realgar As2S2, orpiment As2S3, and arsenic pentasulphide As2S5.

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