Diamonds in the rough - reconsidering the scientific and heritage value of heat-altered stones in prehistoric archaeology through a systematic literature review

This study examines heat-altered stones (HAS), namely rocks that were heated and used by past people and found abundantly at archaeological sites. These stones offer valuable insights into the lifeways of past societies, including their cooking practices, diet, and use of fireplaces. HAS have been recovered in sites dating back to the Pleistocene, suggesting that even before the advent of farming and herding, people were heating stones for cooking and other activities. HAS continued to be used for thousands of years, evolving alongside the adoption of new tools and food systems. Although archaeologists have often found, recorded, and sometimes collected these stones, in-depth studies of HAS remain rare. Here we compiled existing knowledge on HAS, exploring their geographic and chronological origins, their uses, and how scholars have analysed them. Much remains unknown, especially concerning HAS from Africa, Oceania, Asia, and South America. Expanding research to include these regions can deepen our understanding of how ancient cultures used fire, prepared food, and shared these practices globally.