An indigo-based pigment... from an overlooked recipe in a 13th century Arabic text. Fascinating experiments & scholarship from Joumana - & highlighting the digitised manuscript treasures in our libraries!
https://majnouna.substack.com/p/false-red-fake-blue

#indigo #LapisLazuli #lazurite #dye #pigment #ArtHistory #manuscript #libraries #sustainability #JoumanaMedlej

Nepheline syenite with sodalite.
#Sodalite Na8(Al6Si6O24)Cl2 is royal blue varieties widely used as an #ornamental #gemstone. It is a member of the sodalite group with #lazurite, #tugtupte and etec.. First discovered by Europeans 1811 in #Greenland. It is one of the most beautiful #stones for me.

#geo #geology #mineral #Earth #science #feldspathoid #minerology