Mirrors did not play a significant role in interiors until the 16th century when Venetians perfected the method of making flat panes of clear glass, and did not become affordable and mercury-free until 1835 when the German chemist Justus von Liebig invented the silvered-glass mirror. Today, the criteria we use for choosing a mirror are size, shape, and frame design with little thought to the glass itself. But there was a time when even the most elaborately carved and decorated frames – whether gilded, embellished with intricate inlay, or set with gemstones – were only a fraction of the cost of the actual mirror. Because the mirror was so incredibly expensive, frames had to befit the precious glass, not the other way around.
Archeologists recovered the first known mirrors from graves in modern day Turkey and dated them to approximately 6000 BCE. They were round, slightly convex, and highly polished obsidian objects designed for the hand. For the next seven thousand years, mirror development occurred in Egypt, across the Roman Empire, the Middle East, Asia, and Central and South America. What these mirrors have in common across cultures is a relatively small size designed to be cupped in the palm or held in the hand by means of a handle, pierced and strung from a cord and hung on a wall, or placed on a stand for a tabletop. Whether obsidian, anthracite, wet stone, or copper, they were precious and luxurious objects. Some classical Greek examples in bronze integrated three-dimensional figures, and some obsidian mirrors found in South America from 1925 BCE have copper frames and precious stones. The ancient Romans knew how to cast glass and are thought to have learned glass blowing techniques from slaves and craftsmen from the Syro-Palestinian region in the first century BCE. Romans most commonly used glass for vessels but also made mosaic tiles and windowpanes with varying degrees of thickness and transparency.
The method of making flat panes of clear glass from blown cylinders began in Germany and evolved through the Middle Ages until perfected by the Venetian glassmakers on the island of Murano in the 16th century. The Venetians used lead glass for its clarity and workability and applied an amalgam of tin and mercury to the back of a smooth sheet of glass. The result was a relatively large, flat expanse of clear reflective glass. What occurred over the next century was the equivalent of the “cold war” of mirror making. The French and English eventually learned of the Venetian’s mercury-process recipe through espionage and French workshops industrialized the process. The completion of the Hall of Mirrors at Versailles in 1684 was a watershed moment in mirror history. The dimensions and quantity of the 357 mirrors attested to France’s political success, military and diplomatic victories, and economic prosperity at the time. It would take another 150 years until large-scale interior mirrors could be produced safely and cost effectively for the mass market.