Overview
- Researchers from Shandong University analysed fallen fragments from three Huashan sites using infrared, x‑ray and proteomic methods to identify the paint recipe and binding materials.
- The team found red clay rich in nano‑hematite as the pigment and a mortar of slaked lime mixed with small amounts of blood that produced biomineralised calcium carbonate around pigment particles.
- Proteins consistent with human and animal blood, including markers more common in pregnancy and lactation, were detected but the claim that the blood came from childbirth is tentative because those proteins are not uniquely diagnostic and no ancient DNA was recovered.
- The researchers argue the protein‑induced calcium carbonate formed a tight, inorganic shell that chemically anchored pigment to the karst limestone and explains survival in a hot, humid monsoon climate.
- The work recasts the Huashan images as the product of deliberate chemical technique with conservation implications, and experts say broader sampling, aDNA tests and spatial motif analysis are needed before firm cultural or ritual conclusions are drawn.