Little can be said about coarse stone tools, not least because few have been found; no systematic survey has been undertaken; and they can be hard to date precisely when not found in a sealed, datable context. That said, reports on coarse stone tools can be found in several excavation reports (eg the Slackbuie ASDA site: EHG3271; Clarke 2012).
Saddle querns are known to have been used during the Neolithic period, although it is also known that their use extended into the Iron Age and overlapped with the use of rotary querns then. Joanna Close-Brooks described the saddle quern that had been found in the disturbed fill of the passage tomb chamber at Carn Glas, Kilcoy (MHG9014; Fig. 5.62.1; Close-Brooks 1983; Henshall and Ritchie 2001, 143–6 and fig. 33), plus a fragment of a second saddle quern that was found in the filling of the antechamber of the passage tomb at Kilcoy South (MHG9017; Fig. 5.62.2; Close-Brooks 1983; Henshall and Ritchie 2001, 153–7 and fig. 33). A further fragment of a saddle quern was found on the side of the cairn at Kilcoy III (MHG9015; Close-Brooks 1983, 284–5) and was thought by Anthony Woodham, who excavated at Kilcoy, to have been gathered from a nearby field. The three Kilcoy, Easter Ross examples could be of Neolithic date, and investigation of the area around the monuments is recommended to check whether any traces of Neolithic settlement may exist. An indisputably Early Neolithic example of a saddle quern is the one from the pre-long cairn phase of activity at Camster Long, Caithness (MHG1809; Davidson and Henshall 1991, fig. 22).
Some other finds of saddle querns in Highland Region may date to the Bronze Age or Iron Age: candidates for the latter date are the worn example found at the base of the stairwell inside High Pasture Cave, along with eight complete examples found deposited upside-down in an Iron Age context there, plus fragments of others (MHG32043; Uamh An Ard Achadh (High Pasture Cave) (high-pasture-cave.org). As for the trough quern from Auchteraw (Blar an Ruighe), Inverness-shire (MHG2572) that was published by Close-Brooks (1983, 282, 284, fig. 1.3), this may post-date the Neolithic period.