Prussian blue: the first purely synthetic pigment
A synthetic pigment, a deep blue that appeared in a workshop by accident around 1706. Nothing of that blue had previously been found in the earth, in a plant or in a mollusc.
The colour maker Diesbach was preparing Florentine lake in Berlin, a red pigment from cochineal: the extract is precipitated with alum, iron sulfate and potash. His potash ran out, he borrowed some from the alchemist Dippel, and the borrowed potash was spoiled by residues of animal oil, that is, contaminated with hexacyanoferrate; instead of a red precipitate a blue one came down.
The blue appeared a century and a half before Perkin's mauveine and then became a subject of chemistry in its own right: from it Scheele obtained prussic acid in 1782, and the composition of that acid, determined by Gay-Lussac, showed that the pigment holds cyanide, which took its name from the blue.
Why this date
Approximate. Kraft (2008) argues as follows: Dippel arrived in Berlin in the autumn of 1704 and left early in 1707, so the invention most probably took place in 1705 or 1706; the year 1706 stands in the Berlin records and is accepted in the literature (Kraft 2018, Delamare 2019). First printed mention: Frisch's notice Notitia Coerulei Berolinensis nuper inventi, Miscellanea Berolinensia 1 (1710), pp. 377-378. The account of the circumstances of the discovery goes back to a book of Stahl's of 1731, and Kraft warns outright that the discovery is still enigmatic and has not been well researched.
What it grew from
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Mordant dyeing: alum fixes the colour
influenced · Confidence: medium
The blue came down inside the recipe for a lake pigment which, like mordant dyeing, used alum: Diesbach was precipitating a cochineal extract with alum, iron sulfate and potash, and it was the iron of that recipe which, with the spoiled potash, gave a blue precipitate instead of a red one.
Dispute: The whole account of the circumstances goes back to Stahl's book of 1731, that is, it was written down a quarter of a century after the event and not by a participant. Kraft, while giving it as the most probable version, says in the same breath that the discovery is still enigmatic and has not been well researched, and that Stahl gives no date. The link is therefore exactly as firm as Stahl is.
Link sources
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 61-62 Verified 25 Sep 2026
Diesbach was attempting to produce Florentine lake, a red pigment based on cochineal red. Usually he did this by precipitation of an extract of chochineal (produced by boiling dried cochineal insects with water to extract the carminic acid) with alum (KAl(SO4)2.12H2O), iron sulfate ("Vitrioli Martialis"), and potash ("Sale alcalico Tartari").
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 61-62 Verified 25 Sep 2026
However, having no more potash, he borrowed some from Dippel that had been used in his animal oil production. This potash was contaminated with hexacyanoferrate; and therefore the addition of contaminated potash to the solution, which already contained iron sulfate, resulted in a blue precipitate
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 61-62 Verified 25 Sep 2026
Node sources
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 61-62
Diesbach was attempting to produce Florentine lake, a red pigment based on cochineal red.
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 61-62 Verified 25 Sep 2026
However, having no more potash, he borrowed some from Dippel that had been used in his animal oil production. This potash was contaminated with hexacyanoferrate; and therefore the addition of contaminated potash to the solution, which already contained iron sulfate, resulted in a blue precipitate
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 64
Since Dippel arrived in Berlin in the autumn of 1704 and left Berlin early in the year 1707, the invention of Prussian Blue most probably took place in 1705 or 1706.
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008)
The conventional story of the invention of Prussian Blue was told by Georg Ernst Stahl (1660-1734) in a book he published in 1731.
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008)
The discovery of Prussian Blue is still enigmatic and has not been well researched.
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 65
In 1782 Scheele discovered hydrogen cyanide by heating Prussian Blue with diluted sulfuric acid
- Kraft A. «On the Discovery and History of Prussian Blue», Bulletin for the History of Chemistry 33 (2), 61-67 (2008), 65
in 1811 Gay-Lussac's determination of the composition of hydrogen cyanide led to the conclusion that Prussian Blue contained cyanide
- Kraft A. «What a chemistry student should know about the history of Prussian blue», ChemTexts 4, 16 (2018) Verified 20 Sep 2026
The discovery of this new blue pigment by the color maker and former army officer Johann Jacob von Diesbach and the theologian and alchemist Johann Conrad Dippel in 1706 in Berlin.
- Kraft A. «What a chemistry student should know about the history of Prussian blue», ChemTexts 4, 16 (2018) Verified 20 Sep 2026
Frisch JL (1710) Notitia Coerulei Berolinensis Nuper Inventi. Misc Berolin 1:377-378
- Delamare F. «Teindre au bleu de Prusse, une aventure française», Technologie et Innovation 4 (4), 1-15 (2019), 4 Verified 20 Sep 2026
Le « bleu de Prusse » est découvert à Berlin par Dippel et Diesbach en 1706.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.