This YouYube video from Business Insider goes into the history and making of several of the most expensive artist pigments and materials.
I found the first 10 minutes particularly of interest for going into greater depth than usual in describing the mining and refinement of Lapis Lazuli, the semi-precious stone used to make the original Ultramarine Blue – a pigment more expensive by weight than gold (as opposed to the inexpensive synthetic French Ultramarine Blue that we commonly use today).
