Blue pigments in Central Asia

[Merlkir]

If textile dyes are in any way useful, I would suggest looking at the Tarim/Xinjiang textiles. No idea what kind of pigments they used (it might be in the book by Elizabeth Wayland Barber, but I can't remember anything off the top of my head), but there's definitely a lot of reds, yellows and also blues.
Other sources could be the textiles from Noin-Ul and even from Pazyryk. (pazyryk iirc had some leather and wood objects as well)

Or ask the guys at Eran ud Turan, they have some rather deep blue bits in their kit: https://www.facebook.com/pg/eranudturan/...e_internal