Before man-made mirrors, people would have looked at themselves in places where reflections occurred naturally. Ice and bodies of still water in dark places would have provided reflections.
The first examples of purpose-built mirrors are believed to be at least 6000 years old. Samples and fragments of these, made from obsidian, a black volcanic glass, have been found in Turkey.
Various materials have been used as mirrored surfaces through history. The ancient Egyptians used polished copper for mirrors, typically in a round face with decorations added around the outside.
This and other polished metals were also used by Mesopotamians. Examples of polished stone dating back to 2000 BC were used in Central and south America.
Metal alloys of tin and speculum, and the earliest examples of bronze and copper mirrors emerged in China around the same period. These precious metals were luxury items that only the richest individuals could afford.
Metal coated glass mirrors are believed to have been created in Sidon (modern Lebanon) in the first century AD. The Romans used molten lead on blown glass for a rather crude mirror.
By 77 AD, there is evidence of a more refined version backed with gold leaf, in the Roman writer Pliny’s Natural History.
Coatings recognizable as modern mirrors emerged as early as 500 AD. Amalgams of silver and mercury were used to produced mirrors in China, and tin-mercury combinations were perfected by European glass makers, notably in 16th-century Venice.
Famous mirror manufacturers emerged in Europe from this time, notably the Saint-Gobain factory, established as a royal supplier to Louis XIV, but later adapting to cater for a mass market with a great demand for mirrors.
German and Bohemian glass was somewhat cheaper, but glass remained an expensive material. Mass production arrived in the 19th century, and mirrors became more affordable with the refinement of the silvering process.
Silver nitrate is chemically reduced to deposit a thin layer of silver onto glass, in a process invented by the German chemist Justus von Liebig in 1835.
Mirrors had been in use as scientific instruments for centuries. The Greek mathematician Diocles proved the focal properties of parabolic mirrors in the second century BC.
A couple of centuries later, Ptolemy experimented with polished iron mirrors in various convex, concave and spherical forms.
Besides their familiar use in decoration and interior design, glass mirrors continue to play a valuable role reflecting and directing light in art, film and television as well as science and technology.