Progress on the identification of prehistoric heat-treated lithic artifacts

<p indent="0mm">Heat treatment demands a sophisticated knowledge of fire and an elevated cognitive ability. It is a challenge to identify heat treatment lithic artifacts in specific archaeological materials. Not all heated lithic artifacts are the result of intentional heat treatment, as natural fires and other human-use fire activities can also lead to alterations in the surface and internal structure of stones. Identifying heat-treated stone products and confirming the existence of ancient human heat treatment practices at the site poses a challenge. This paper reviews the concept of heat treatment and summarizes the macro identification methods and archaeological techniques for heat-treated lithic artifacts discovered in recent experimental archaeology. These include color shift, changed gloss, reduced surface roughness, and heat-induced non-conchoidal fractures (HINC), tempering residues, infrared spectroscopy, and thermoluminescence analysis, etc. This paper posits that combining spatial recognition of lithic artifacts assemblages with comprehensive studies of individual artifact information is a reliable method for identifying heat treatment lithic artifacts. Employing multiple methods to identify heated lithic artifacts at prehistoric sites and to investigate the underlying causes is crucial for understanding the advancements in ancient human fire-use technology and the evolution of cognitive abilities in East Asia.