spigolo

Spigolo, plural spigoli, is the Italian term for the edge of a solid object—the straight line along which two faces meet. In geometry, a spigolo is the line segment that forms the intersection of two plane faces of a polyhedron. For example, a cube has 12 spigoli. The corresponding point where faces meet is the vertice, while the angle formed by two intersecting lines is an angolo.

In practical use, spigolo describes the physical edge of objects such as stone, metal, or wood. Edges can be left sharp (spigolo vivo) or modified for safety or aesthetics by chamfering or rounding, yielding a spigolo smussato or a radiused edge. This distinction is common in manufacturing, carpentry, and sculpture, where edge quality affects handling, wear, and appearance.

Beyond solid geometry, the concept of spigolo appears in architecture, crystallography, and geology to denote the boundaries between adjacent surfaces or facets. In these fields, precise terminology helps specify which edge is being referenced, especially when describing texture, cutting plans, or facet arrangement.

In Italian, spigolo is the standard term for an edge; related terms include vertice for the vertex at a corner and angolo for the angle formed by lines. The noun may appear in bilingual technical texts and is sometimes found in discussions of design, engineering, and material processing.