---
title: "Prussian blue was discovered accidentally in 1706 as a failed attempt to make a red pigment"
type: "claim"
status: "seedling"
source_url: "https://en.wikipedia.org/wiki/Prussian_blue"
source_title: "Prussian blue (Wikipedia)"
source_author: "Wikipedia contributors"
source_date: "2026-07-09T00:00:00.000Z"
source_quote: "Diesbach was attempting to create a red lake pigment from cochineal, but obtained the blue instead as a result of the contaminated potash he was using. He borrowed the potash from Dippel, who had used it to produce his animal oil."
source_tier: 4
audit_status: "capture-verified"
writer_model: "claude-opus-4-8"
provenance: "Promotion from 10-inbox/raw/2026-07-09-hop-prussian-blue-radiological-antidote.md, 2026-07-11"
origin: "batch"
derived_from: "10-inbox/raw/2026-07-09-hop-prussian-blue-radiological-antidote.md"
date_created: "2026-07-11T00:00:00.000Z"
tags: ["dye-chemistry","pigments","accidental-discovery","history-of-chemistry","hop"]
drafted_in: ["2026-07-13-made-to-leave","made-to-leave"]
---


Prussian blue — ferric hexacyanoferrate — is generally credited as the first modern synthetic pigment, and its discovery is a canonical accident. In Berlin around 1706, the paint-maker Johann Jacob Diesbach set out to make a red cochineal lake pigment. He finished the batch with potash borrowed from the alchemist Johann Konrad Dippel; that potash was contaminated with Dippel's "animal oil," a bone/blood distillate. The reaction produced a deep blue precipitate rather than the intended red: "Diesbach was attempting to create a red lake pigment from cochineal, but obtained the blue instead as a result of the contaminated potash he was using."

The core of the story — Diesbach, Berlin, ~1706, a cochineal red gone wrong yielding iron ferrocyanide — is standard chemistry history. Dippel's specific role, however, is weaker: the source article itself notes the detail is not corroborated by other historical accounts, making the "borrowed contaminated potash" attribution folklore-adjacent even where the accidental-blue outcome is well attested. The single source here is Tier 4, so the biographical particulars remain provisional; independent verification against a primary or scholarly history is tracked in [[question-verify-prussian-blue-1706-accidental-discovery-primary]].

The claim sits in the vault's recurring pattern of consequential accidental discoveries — compare [[claim-chest-compression-cpr-discovered-by-accident]] and [[claim-kouwenhoven-electrocution-research-produced-defibrillator]], where an unintended observation became a durable technique. The pigment's afterlife is where it turns cross-domain: the same 1706 compound is now [[claim-prussian-blue-is-the-fda-approved-antidote-for-radioactive-cesium-and-thallium|an FDA-approved radiological antidote]]. It also sits adjacent to the vault's other pigment-and-color chemistry, such as [[claim-kubelka-munk-theory-devised-1931-for-paint-opacity]].

> [!note] Seek's commentary:
> The Dippel thread is exactly the kind of vivid detail that survives in retellings because it's a good story, not because it's well sourced — the same shape as the Dippel/Frankenstein legend the capture wisely declined to promote. I kept the note but leaned the weight onto the uncontested core. — Seek