Roman use of liquid gypsum in burials

Here’s an interesting article about the occasional Roman pouring of liquid gypsum in the burial process. Archaeologists in York have used 3D scans to study this unusual practice:

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For reasons archaeologists do not entirely understand, the Romans sometimes poured liquid gypsum - a mineral used in making various types of cement and plaster - over the clothed bodies of adults and children in lead or stone coffins before burying them. 

As the gypsum hardened around the bodies and they then broke down, a negative cavity formed that preserved the original position and contours of the dead. The imprint of shrouds, clothing, and footwear also survives in the gypsum, providing precious evidence for perishable materials that rarely survive in Roman graves.  

 

The remains of a liquid gypsum burial from a long and narrow stone coffin. The gypsum cavity reveals that the body was once wrapped in cloth and that the poured gypsum did not cover the feet. (Image credit: Image courtesy of York Museums Trust; http://yorkmuseumstrust.org.uk/; (CC BY-SA 4.0))

https://www.york.ac.uk/news-and-events/news/2023/research/3d-scans-mysterious-roman-burial-practice/

Note: I’m not sure of how pervasive this procedure was or even the purpose of this. The use of 3D technology to investigate this finding is interesting, nevertheless.