Sort of an art ping.
Have you heard of this pigment? Is there anything equivalent in use now?
I’ve heard of it. We prob have many shades that are the equivalent but the importance of it is the fact that the Egyptians had found a way to make such a color, that lasted so long, over 1000 years, and retain it’s luminescence.
http://www.webexhibits.org/pigments/indiv/overview/egyptblue.html