Field of Science

van Gogh's Palette

In an attempt to brighten a dreary Philadelphia day, I pulled out a coffee mug that glows with Vincent van Gogh's sunflowers. Among the most vivid of his favorite pigments is chrome yellow. Chrome yellow was first isolated from a natural source (the mineral crocoite) in the late 18th century by Parisienne chemist Vauquelin. By the late 19th century, when van Gogh's sunflowers took form, the vibrant yellow was one of a series of new and exceptionally vivid colors. Chrome yellow is actually a lead salt, lead chromate (PbCrO4. The pigment isstill used today but it has been replaced in many cases by similarly colored, less toxic organic pigments. Unfortunately chrome yellow degrades over time, so that the once brilliantly glowing sunflowers now appear to be dry, drab ocher shadows of van Gogh's vision.

Perhaps influenced by the mug, this week's webcast general chemistry example problem is based on a simple inorganic synthesis of the chrome yellow pigment. One of my colleague's uses another synthesis. in her course on "The Stuff of Art"


Read more about the history and chemistry of color in Bright Earth: Art and the Invention of Color by Philip Ball.

7 comments:

  1. Ooh, continuing with the webcasting--how fun! My talk about your work went really well. I should have teleconferenced you in or something. I just didn't think of it.

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  2. As the editor for the Women in Science Top Ten Sources and a regular reader of Culture of Chemistry, thanks for the comment!

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  3. As a doctoral student in bioanalytical chemistry, I really enjoyed this post and your blog overall. Thanks!

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  4. I hope your mug doesn't have lead-based pigments. They easily leach into acidic drinks. One of my undergraduates projects many years ago was the extraction of lead from ceramicware with acetic acid.

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  5. Aorstan...

    The color is on the outside of the mug, which purports to be lead free!

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  6. "Unfortunately chrome yellow degrades over time, so that the once brilliantly glowing sunflowers now appear to be dry, drab ocher shadows of van Gogh's vision." ...well said.

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