Mullers (handstones, manos, riders) are used for grinding materials such as wheat; its is the upper element of the grinding apparatus, a handheld flattish tool ground against the lower element, a quern with a relatively large surface area. Methods for shaping depending on the stone type: chert may be chipped; limestone may be pecked and ground. Some mullers have pecked indents for fingers.
Such tools are small enough to have been manipulated with one hand although they were doubtless normally used -- in a backwards-forwards motion -- with two hands. ... The working surface of a muller resulted from a combination of preliminary shaping and roughening, use on a quern, and period pecking to restore the grinding efficiency. Mullers were held flat against the quern's grinding surface during use and the direction of movement was along the long axis of the quern. Secondary modification of mullers includes signs of use, burning, and reworking. Moholy-Nagy 1983
Querns (saddle querns, quern stones, metates) are relatively large objects against which a handheld muller is ground, to grind materials (for example, wheat). The function of a quern is comparable to a mortar in a mortar-pestle grinding apparatus. A quern is similar to a pecked and ground slab. However, the former tends to be smooth and either flat or concave; and the latter is either convex or flat, and with a rough pecked surface.
The working surfaces of the querns tended to be smooth and to some degree concave. There were some examples on which the working surfaces appear to have been "sharpened" by pecking. ... There is a considerable variety of forms. This variety may, at least in part, be merely a function of the length, breadth, thickness, and hardness of the pieces of stone that were randomly available ... There are also degrees of difference in the amount of concavity of the working surfaces, some of which are also provided with secondary (mortarlike) depressions. Moholy-Nagy 1983
Pecked and ground slab
Pecked and ground slabs are artifacts the surfaces of which were evidently utilized both for grinding and cracking of such materials as coloring matter and nuts. Their grinding surfaces tend to be convex (in a few traces almost flat); they are wider than the items we classify as mullers, and shorter than our querns. Some items listed under mullers might equally well be classified in this group. The working surfaces are prepared by pecking, then generally smoothed, especially in the center of the working face. The slabs are of the same kinds of stone as the querns and were probably manufactured by the same techniques. Shaping of the edges generally seems to have depended on the kind of stone used, and in no case is it extensive. The edges of the slabs of chert appear to be unmodified, but the edges of the limestone examples are ground to some extent. Moholy-Nagy 1983
Utilized cobbles are large, rounded, probably waterworn stones. They are essentially unworked, but exhibit marks of grinding, pecking, or pounding, or they may bear scratches or cuts, or a combination of these marks of use. They probably served a number of different purposes -- as hammerstones, rubbing stones, or perhaps as anvils in artifact manufacture. Moholy-Nagy 1983
Pestles are the upper implement of a mortar and pestle, the former being a bowl-like implement against which the latter can be ground to pulverize materials.
Pestles, as the term implies, are elongated, unusually well-made artifacts that have straight sides usually tapering toward one end, flattened to rounded ends, and approximately round cross sections. They were normally finished by overall grinding. These artifacts were shaped by pecking, the marks of which were then practically obliterated by careful grinding. Presumably, they were used to mash and grind substances in the mortars to be described below. Their size, weight and hardness would have made them very useful as crushers when used with either one or both hands. Moholy-Nagy 1983
Though their shape is like the miniature "pestlelike" small borers, the larger scale of true pestles differentiates them. Also, pestles may be compared to hammerstones, which can be described as spherical pestles; and also to pestle-hammerstones, which are intermediate between a pestle and a hammerstone.
The form and size of the pestle-hammerstone is intermediate between a large, heavy, elongated pestle and a relatively spherical hammerstone. Pestle-hammerstones may even reasonably be grouped as pecking and rubbing stones. Indeed, not even the original utility of pestle-hammerstones is entirely clear. They are mainly very hard, for example of chert or chalcedony, and range from slightly smaller than golf balls to slightly larger than tennis balls and occasionally even the size of a grapefruit. Creative theories regarding their use have been published,
It would be tempting to suggest that these objects were sling missiles, ready at hand for the defence of the mound slope. [Though this theory was cautiously discredited.] Moholy-Nagy, 1983
Mortars are large, heavy, bowlike artifacts with smoothed interiors. They were probably used, in combination with the large pestles described previously, to break up and grind foodstuffs and perhaps other substances as well. Unlike the back-and-forth motion of a muller on a quern, the action of a pestle on a mortar would presumably have been either percussive or rotary. Mortars and mortar fragments were very often found reused in stone wall foundations. Some "mortars" may have been reused as doorpost pivot stones. Moholy-Nagy 1983
The finest mortars are like thick-walled bowls, while the crudest are merely boulders with depressions. Some boulders may have several distinct depressions.
Palettes or pigment-grinding stones are medium-sized flat pieces of relatively fine-grained stone that show some hollowing on one or two faces. They presumably were used as nether stones in the grinding of mineral materials into powder form. ... They were carefully made with all surfaces ground and no peck marks visible. ... There are, however, less carefully made examples which show more pecking than grinding Moholy-Nagy 1983
Retouchers are smooth, flat pieces of stone that fit comfortably in one hand and may have been used for retouching flint or obsidian artifacts. ... The smooth surfaces and comfortable shapes of these pebbles first led to their classification as polishing stones. Reexamination of their pocked faces and ends suggests that they resemble artifacts Semenov has identified as pressure-retouching tools used in knapping. ... On the retouchers, pocking is concentrated toward the ends and edges but sometimes occurs in the center of the faces as well. In addition to pocking, the faces of the retouchers also bear numerous fine scratches, sometimes parallel to each other, sometimes not. Such signs of use are usually bifacial. ... [Usually] the pebbles do not appear to be artificially shaped. Moholy-Nagy, 1983
Rubbing stones are similar to mullers, only too small. They can be pecked all over (a pecked rubbing stone) or not at all. They generally have one or both sides worn; or barely at all, depending on the extent of utilizations.
Polishing tools consist of smooth, fine-grained, waterworn stones that show signs of use in the form of faint parallel transverse striations, scratches, wear facets, or pecked edges. The characteristic that distinguishes them most clearly from our rubbing stone group, however, is their shiny surfaces. Presumably, they were used for finer finishing work. Moholy-Nagy, 1983
Whetstones are rough-grained stones with one or more faces that are smoothed flat or slightly concave, which suggests their use in the sharpening of stone, bone and shell artifacts. Moholy-Nagy, 1983
Whetstones can have smooth, slightly concave faces; or can also have grooves suggesting that pointed tools like needles, awls or flakers may have been sharpened.