https://www.thoughtco.com/ochre-the-oldest-known-natural-pigment-172032#:~:text=Ochre%20%28rarely%20spelled%20ocher%20and%20often%20referred%20to,iron%20oxide%20which%20are%20described%20as%20earth-based%20pigments.
Thank you for that education on ochre...and the website. I have a new place to visit!