Oldest textile dyed indigo blue found
A George Washington University researcher has identified a 6,200-year-old indigo-blue fabric from Huaca, Peru, making it one of the oldest-known cotton textiles in the world and the oldest known textile decorated with indigo blue.
Read more at: http://phys.org/news/2016-09-oldest-textile-dyed-indigo-blue.html#jCp
Indigo dye requires chemistry!
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