This paper presents the most recent research on querns and millstone quarries carried out in the Balearic Islands of Minorca and Majorca (Spain) since the article published in the proceedings of the Rome colloquium (Sánchez 2011). Twenty-five new extraction sites have been identified (7 in Minorca and 18 in Majorca) raising the total to 64 for both islands. Certain quarries produced thousands of rotary querns, whereas other smaller sites only produced a few. The stones were meant either to grind grains for bread or for animal fodder. Others served the olive oil industry. In Minorca, the querns and millstones were hewn from dune and reef rock deposits. In Majorca, in addition these two types of rock deposits, millstone workings included a variety of limestones, dolomites, sandstones, conglomerates and siliceous stones. Each new site is described according to its lithology and origin (Quaternary eolianites, Pliocene Upper Miocene Tertiary reefs and limestones from the Jurassic). Quarry dating is particularly difficult. At times it can be deduced from comparison with millstones from archaeological excavations. The recently identified modern chert workings in Majorca produced composite millstones in the manner of imported French burrs. The pit quarries exploiting chert are very recent, dated by texts and interviews with local residents. Their millstones served, depending on their quality, to grind either grains for bread, cereals for animal fodder or calcined limestone for cement.