This product was first published in the classic, and the original version was "replaced" and classified as inferior.

"Bielu" said: "Dai Yi was born in the valley of Qi, red and blue, as bright as cockscomb, so he can dye his fingernails."

"The Classic of Materia Medica" said: "Today's doctors choose to take large pieces, the top of which is like a floating tripod, which is called the first generation."

Li Shizhen said: "The mountains are full of ochre, which is good for people who come out from the northwest ... If you learn it as cinnabar, you can order books and benefit from gold."

To sum up, the origin and color of ochre used in ancient times are dark red, and there are round-like protrusions on the surface, commonly known as "nail head", which is consistent with ochre used today.