Pair of sunglasses, the round lenses cut in smoky quartz, th - Lot 331

Pair of sunglasses, the round lenses cut in smoky quartz, the frame in chased and openwork brass. China, late 19th century. Length: 13.5 cm Height: 5.5 cm In the 17th and 18th centuries, two Chinese engineers from the city of Suzhou, renowned for their stonework, developed optical lens technology. Sun Yunqiu (1626-1661) promoted the semi-precious stone lens industry in the 17th century. Later, Chu Sanchan established a workshop in Suzhou in 1735, perfecting corrective lens technology, notably by adding temples, a recent innovation in Europe. The business flourished in cities such as Beijing, Shanghai, Tianjin and Guangzhou, using materials such as rock crystal, amethyst and topaz to produce translucent or transparent lenses.