Vein quartz as a raw material for prehistoric stone tools is a much maligned material, very often treated to a cursory analysis only, if it is analysed at all. This paper examines the role of quartz in Neolithic stone tool traditions through the typo-technological analysis based on experimental archaeology of a Neolithic quartz assemblage from Thornhill, Co. Londonderry, Northern Ireland, and a comparison with a Mesolithic quartz assemblage from Belderrig, Co. Mayo, Ireland. The analysis shows that the Neolithic quartz tradition is distinctly different from the preceding Mesolithic and appears geared towards the production and use of smaller, thinner flakes knapped using a wider range of techniques, combinations of techniques and technical procedures than in the Later Mesolithic. The use of the bipolar technique is interpreted as a social choice based on the lithic traditions of the Neolithic community and not directly related to the use of quartz cobbles or the knapping of small cores. Differences and similarities were noted between the manufacture techniques and treatment of quartz and flint by the community at Thornhill. Moreover, a complex pattern of deposition of both artefactual and natural quartz was identified in the pits and structures, suggesting that quartz played a complex dual role for the inhabitants of the site.