Blind tests have had an important role in the history of functional studies. They have been essential for both demonstrating the accuracy of functional interpretations and for discovering methodological pitfalls, including the problem of equifinality in microwear formation. Functional method for quartz has been in place since the late 1980s, mainly thanks to the pioneering work done by K. Knutsson. While the initial methodological efforts and subsequent archaeological applications have shown that the use of prehistoric quartz tools can be reconstructed in detail and that quartz assemblages can therefore contribute significantly to our understanding of past technologies and behaviours, the strength of the method has never been formally demonstrated through blind testing. We present here the results of a two-part single-analyst blind test involving 25 tools made of xenomorphic (vein) quartz and used either hand-held or hafted for different tasks. The test was aimed at a preliminary evaluation of the performance of low and high magnification approaches as well as their combination. The results are used to discuss the challenges involved in the analysis, and different solutions are proposed for meeting them in future studies.