unfaceted

Unfaceted is an adjective describing something that lacks facets, meaning flat, polished, or planar faces that are typically produced by cutting or cleavage. An unfaceted object has a surface that is not divided into multiple flat faces, and may be irregular or smoothly curved.

In mineralogy and crystallography, facets are flat faces on a crystal that develop along specific crystal planes. An unfaceted crystal lacks deliberately produced flat faces. Natural crystals may still show incidental faces from growth or weathering, but they are not cut or faceted for display or analysis.

In gemology and jewelry, unfaceted stones are those that have not been cut to reveal a pattern of flat surfaces. This includes rough stones as they are mined and stones cut with smooth or curved surfaces, such as cabochons. Unfaceted gems tend to scatter light differently than faceted stones and can display a softer glow or opacity rather than the sharp brilliance associated with faceting.

In optics and manufacturing, unfaceted surfaces refer to components without flat faces. Many lenses or precision-polished parts feature single curved surfaces rather than multiple facets, which can affect light reflection and diffraction. Unfaceted finishing is also used for ceramics, glass, and other materials where a smooth, continuous contour is preferred over angular facets.

Overall, unfaceted describes a lack of flat, geometric facets, with usage varying across mineralogy, gemology, and engineering contexts. See also facet, cabochon, rough, and polishing.