Red lead pigment created by Vincent van Gogh has been shown to be fading . Impurities in the paint may have triggered a chemical reaction in sunlight . Scientists found a rare lead - based oxide has been detected in the paint . This then mixes with carbon dioxide from the air to create white crystals . They warn that many of the artist 's paintings may be at risk of this phenomenon . They examined Wheat ##ing Under a Cloudy Sky and found it had faded .
Red lead pigment used by Vincent van Gogh has been found to be fading . Impurities in the paint may have triggered a chemical reaction in sunlight . Scientists found a rare lead-based mineral has been forming in the paint . This then reacts with carbon dioxide from the air to create white crystals . They warn that many of the artist 's paintings may be at risk of this process . They examined Wheat Stack Under a Cloudy Sky and found it had faded .