Ancient and Modern applications for 'Egyptian Blue'
The distinctive blue pigment used by the ancient Egyptians is the earliest known artificially produced pigment. The earliest compound (CaCuSi4O10) used sand, copper and natron (a natural salt containing sodium carbonate). The process of how to manufacture the pigment, which involves heating, might have been discovered in conjunction with the production of faience (which uses similar compounds).
A second, more expensive 'Egyptian Blue' was used almost exclusively during the Amarna period which contained Cobalt aluminate (CoAl2O4). This colour is commonly seen on 'Malkata ware' pottery where it looks like a pale sky blue today.
Scientists discovered in 2009 that the pigment has outstanding luminescence in near infra-red light, meaning you can see if an object was painted even if you can no longer see the original colour. In the story linked below a new application for this luminesnece has been discovered: it can show up marks (like fingerprints) on patterend and highly reflective surfaces.
It's also been used by the British Museum to study artworks (such as the painted Tomb Chapel of Nebamun and the Elgin Marbles) in a non-descructive manner.
http://www.abc.net.au/news/2016-05-25/ancient-egyptian-blue-pigment-can-help-identify-fingerprints/7442698
The distinctive blue pigment used by the ancient Egyptians is the earliest known artificially produced pigment. The earliest compound (CaCuSi4O10) used sand, copper and natron (a natural salt containing sodium carbonate). The process of how to manufacture the pigment, which involves heating, might have been discovered in conjunction with the production of faience (which uses similar compounds).
A second, more expensive 'Egyptian Blue' was used almost exclusively during the Amarna period which contained Cobalt aluminate (CoAl2O4). This colour is commonly seen on 'Malkata ware' pottery where it looks like a pale sky blue today.
Scientists discovered in 2009 that the pigment has outstanding luminescence in near infra-red light, meaning you can see if an object was painted even if you can no longer see the original colour. In the story linked below a new application for this luminesnece has been discovered: it can show up marks (like fingerprints) on patterend and highly reflective surfaces.
It's also been used by the British Museum to study artworks (such as the painted Tomb Chapel of Nebamun and the Elgin Marbles) in a non-descructive manner.
http://www.abc.net.au/news/2016-05-25/ancient-egyptian-blue-pigment-can-help-identify-fingerprints/7442698
J Lee Here's a tutorial about Egyptian blue from the Royal Society of Chemistry as its a little long to explain in a comment:
ReplyDeletersc.org - Egyptian blue- Learn Chemistry
wow
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