Bossage is uncut stone that is laid in place in a building, projecting outward from the building, to later be carved into decorative moldings, capitals, arms, etc. Bossages are also rustic work, consisting of stones which seem to advance beyond the surface of the building, by reason of indentures, or channels left in the joinings; used chiefly in the corners of buildings, and called rustic quoin

Quoin (architecture)

Quoins are the cornerstones of brick or stone walls. Quoins may be either structural or decorative. Architects and builders use quoins to give the impression of strength and firmness to the outline of a building...

s. The cavity or indenture may be round, square, chamfer

Chamfer

A chamfer is a beveled edge connecting two surfaces. If the surfaces are at right angles, the chamfer will typically be symmetrical at 45 degrees. A fillet is the rounding off of an interior corner. A rounding of an exterior corner is called a "round" or a "radius"."Chamfer" is a term commonly...

ed, bevel

Bevel

A beveled edge refers to an edge of a structure that is not perpendicular to the faces of the piece. The words bevel and chamfer overlap in usage; in general usage they are often interchanged, while in technical usage they may sometimes be differentiated as shown in the image at right.-Cutting...

ed, diamond-shaped, or enclosed with a cavetto or listel.