Bitumen-painted pottery

The excavations at Tell Sabi Abyad between 1996 and 2000 in the so-called Burnt Village, which was destroyed in a violent fire at around 6000 BC, have yielded an intriguing group of ceramics. The vessels are decorated in a most curious manner, always with a very distinctive matt, fugitive black pigment. The rough, primitive-looking decorative style differs remarkably from any other found in the Burnt Village, showing simple vertical stripes, rough 'fish-hook'-like designs and thick dots. We suspected that there was something special about these vessels. What kind of paint could this be?

Loe Jacobs and Bram van As, archaeologists associated with the Department of Pottery Technology of Leiden University, decided to submit some of the sherds to a 'refiring test', which means firing them in a potters' kiln at a temperature of 750⁰ C. Usually this treatment does not affect the Late Neolithic painted designs significantly. In this case, however, the painted decoration simply disappeared. The suspicion arose that we were dealing with an organic pigment. We contacted Jaques Connan, head of the department of inorganic chemistry at the Centre National des Recherches Scientifique (CNRS, Paris). Connan quickly discovered that the pigment was, indeed, an organic substance. In fact, it was bitumen.