Identification of heat-treated lithic artifacts via quantitative surface gloss characterization

Identification of heat-treated lithic artifacts via quantitative surface gloss characterization | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Identification of heat-treated lithic artifacts via quantitative surface gloss characterization Robert Stárek, Yonatan Sahle, Balemwal Atnafu, Martin Moník This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8156574/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 Apr, 2026 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Heat-treated siliceous artifacts from archaeological contexts provide valuable insights into the raw material economy and cognitive prowess of hominins responsible for such a sophisticated and transformative technology. Successful heat treatment induces molecular and structural changes that enhance the mechanical properties of toolstones, ultimately making them more knappable. Among the measurable transformations attained through heat treatment is a reduction in fracture toughness, which reduces the force required for fracture propagation. The internal changes during heat treatment also lead to significantly reduced surface roughness that is visually evident through a characteristically glossy appearance as a result of the improved microscopic smoothness. Reduced surface roughness (i.e., glossiness) is a reliable proxy for improved homogeneity and brittleness, hence fracture predictability. In this study, we present a simple, cost-effective, highly accurate, and field-ready technique for identifying heat-treated siliceous artifacts by measuring gloss as a function of the reduction in surface roughness. Our approach allows archaeologists to overcome the limitation of flat and opaque surfaces required for measurements by conventional gloss meters. Physical sciences/Engineering Physical sciences/Materials science Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 02 Apr, 2026 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 16 Dec, 2025 Reviews received at journal 11 Dec, 2025 Reviews received at journal 11 Dec, 2025 Reviewers agreed at journal 28 Nov, 2025 Reviewers agreed at journal 26 Nov, 2025 Reviewers invited by journal 25 Nov, 2025 Editor invited by journal 25 Nov, 2025 Editor assigned by journal 22 Nov, 2025 Submission checks completed at journal 22 Nov, 2025 First submitted to journal 19 Nov, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8156574","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":552202078,"identity":"d0d19bfc-d477-4dfe-9892-12478a227d48","order_by":0,"name":"Robert 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