Recognising burnt vein quartz artefacts in archaeological assemblages

• Published in: Journal of archaeological science 2011-09, Vol.38 (9), p.2251-2260
• Main Authors: Driscoll, Killian, Menuge, Julian
• Format: Article
• Language: English
• Subjects: Analysis of archaeological features; Burning experiment; Decrepitation; Fluid inclusions; Lithics; Methodology and general studies; Prehistory and protohistory; Vein quartz
• ISSN: 0305-4403; 1095-9238
• DOI: 10.1016/j.jas.2011.03.028

The primary aims of this study were to determine how vein quartz behaves in an open wood fire and to suggest how burnt quartz may reliably be distinguished from unburnt quartz. Experimental burning was conducted on 10–50 mm pieces of knapped quartz collected from outcrops and beach cobbles near a later Mesolithic and Neolithic quartz scatter at Belderrig, north County Mayo, Ireland. Burning resulted in considerable fragmentation, with the majority of post-burning fragments 5 μm fluid inclusions in quartz lost their fluid contents, often with the development of fluid escape structures, and this is likely to be a reliable discriminant between burnt and unburnt vein quartz generally, even in the absence of unburnt material for comparison. Burning also creates microfractures, but this feature does not provide a diagnostic test of burning as there is considerable overlap between burnt and unburnt samples in microfracture density. ► Experimental open fire burning to distinguish burnt from unburnt quartz lithics. ► Examining visible characteristics, fragmentation rate, and spatial distribution. ► Burnt and unburnt samples were examined macro- and microscopically. ► Microscopic detection of fluid inclusion decrepitation diagnostic of quartz burning. ► Macroscopic changes diagnostic of burning where similar unburnt quartz available for comparison.