As it happens, rubies are one of Dr Subramanian’s inspirations. His hope is that by piggybacking on the structure of their crystals － already known to yield an appropriately, well, ruby, colour － he might be able to reproduce the effect. A weakness of this approach is that rubies themselves make an unstisfactory pigment. When crushed, they become pale pink.
Pigment － Studying scarlet The Economist July 13th 2019 赤色色素
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