https://www.sciencedirect.com/science/article/abs/pii/S0305440311001816 https://www.sciencedirect.com/science/article/abs/pii/S03054... " natural earths, miner

https://www.sciencedirect.com/science/article/abs/pii/S0305440311001816 https://www.sciencedirect.com/science/article/abs/pii/S03054... " natural earths, minerals and rare artificial pigments. Paintings are made up of thin paint layers (0.01–0.10 mm thick) strongly adhering to the underlying preparation layer." https://www.sciencedirect.com/science/article/abs/pii/S1386142508006136 https://www.sciencedirect.com/science/article/abs/pii/S13861... " To obtain the green color, green earths and malachite were used, together with mixture of Egyptian blue and yellow ochre."