specchi

Specchi is the Italian term for mirrors, reflective surfaces that form images by light reflection. In most everyday use, a specchio is a pane of glass with a reflective backing, typically producing a virtual image behind the surface when used as a plane mirror. When the surface is curved, specchi can converge or diverge light to produce magnified, reduced, or inverted images, depending on curvature and distance.

Three basic shapes are most common: plane, concave, and convex. Plane specchi preserve the size and orientation of objects but may reverse left and right. Concave specchi can enlarge distant objects or focus light, while convex specchi produce diminished, upright virtual images and wider fields of view.

Manufacture and coatings: modern specchi use glass coated on the back with a reflective metal such as aluminum (and historically silver). A protective layer is applied to prevent corrosion. Dielectric coatings may be used in specialized optics to tailor reflectivity for specific wavelengths or improve durability.

Historically, mirrors began as polished metals; later glass mirrors with metallic backing emerged in the early modern period, with notable production at Murano. The 19th and 20th centuries saw the adoption of silvering and, later, aluminum deposition, making mass production of high-quality mirrors feasible.

Etymology: specchio comes from Latin speculum, meaning a reflecting surface or instrument for looking. The term specchi is the plural in Italian, used to refer to mirrors in general and in various technical terms in optics and architecture.