from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A soft orange-red arsenic ore, As2S2, used in pyrotechnics and tanning and as a pigment.

from The Century Dictionary.

  • noun Arsenic disulphid (As2S2), a combination of an equal number of sulphur and arsenic atoms; red sulphuret of arsenic, which is found native in transparent crystals, and also massive.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Min.) Arsenic sulphide, a mineral of a brilliant red color; red orpiment. It is also an artificial product.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun mineralogy A mineral, arsenic sulfide (AsS), often associated with orpiment and stibnite in lead, silver and gold ores.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a rare soft orange mineral consisting of arsenic sulphide; an important ore of arsenic


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English, from Medieval Latin, from Catalan, from Arabic rahj al-g̣ār, powder (of) the mine or cave : rahj, powder + al-, the + g̣ār, cave; see g̣rr in Semitic roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

Old English, from Medieval Latin, from Arabic رهج الغار (rahj-al-ğār, "cave dust").


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  • Among the items quickly snapped up was an exquisite orange and yellow glass piece made to imitate realgar, a poisonous mineral that is almost pure sulphide of arsenic, beautiful to the eye but poisonous to the touch (price: around €2,000).

    In Maastricht, No Sign of Crisis

  • Several other, less-common minerals contain arsenic, including orpiment, realgar, and enargite, which are arsenic sulfides.


  • Such are the kinds of stones that cannot be melted, and realgar, and ochre, and ruddle, and sulphur, and the other things of that kind, most


  • It occurs as metallic arsenic, which is of a steel-grey colour, brittle, and gives off a garlic-like odour when heated; as arsenious acid; in the form of two sulphides -- the red sulphide, or realgar, and the yellow sulphide, or orpiment; and as arsenite of copper, or Scheele's green.

    Aids to Forensic Medicine and Toxicology

  • This is procured by mixing massicot, or Naples yellow, with a small quantity of realgar, and a very little Spanish white.

    Young's Demonstrative Translation of Scientific Secrets

  • Take of nitrate of baryta, twenty-seven parts, by weight; of sulphur, thirteen; of chloride of potassa, five; of realgar, two; and of charcoal three parts.

    Home Pastimes; or Tableaux Vivants

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

    Young's Demonstrative Translation of Scientific Secrets

  • ~ Arsenic occurs in considerable quantities in nature as the native element, as the sulphides realgar (As_ S_ ) and orpiment

    An Elementary Study of Chemistry

  • Orange-coloured grounds may be formed by mixing vermilion or red lead with King's yellow, or orange lake or red orpiment (? realgar) will make a brighter orange ground than can be produced by any mixture.

    Handbook on Japanning: 2nd Edition For Ironware, Tinware, Wood, Etc. With Sections on Tinplating and Galvanizing

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

    The Economic Aspect of Geology


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  • "On an even more sinister level, herbs were more versatile and effective than spices as poisons. Aconite (hellebore), hemlock, and digitalis were known to be poisonous, whereas spices did not have this danger (although arsenic, known in the medical manuals as realgar, could be listed as a spice in merchant handbooks)."

    Paul Freedman, Out of the East: Spices and the Medieval Imagination (New Haven and London: Yale UP, 2008), 62

    November 28, 2017