Ashlar is finely dressed (cut, worked) masonry, either an individual stone that has been worked until squared or the masonry built of such stone. It is the finest stone masonry unit, generally cuboid or less frequently trapezoidal. Precisely cut “on all faces adjacent to those of other stones”, ashlar is capable of very thin joints between blocks, and the visible face of the stone may be as quarry-faced or feature a variety of treatments: tooled, smoothly polished or rendered with another material for decorative effect. In some Masonic groupings, which such societies term jurisdictions, ashlars are used as a symbolic metaphor for progress. As described in the explanation of the First Degree Tracing Board, in Emulation (and other) rituals the rough ashlar is a stone as taken directly from the quarry, and allegorically represents the Freemason prior to his initiation; a smooth ashlar (or "perfect ashlar") is a stone that has been smoothed and dressed by the experienced stonemason, and allegorically represents the Freemason who, through education and diligence, has learned the lessons of Freemasonry and who lives an upstanding life.