Known. Some of the bronze mirrors still reflect after about 2,000 years.
More than 80 mirrors were found in a large Han cemetery at Dabaozi Village, in Xianyang City, Shaanxi Province. The graveyard is at Gaozhuang Township, and it holds about 400 tombs. The Han dynasty lasted from 202 BC to 220 AD. The mirrors are about 7 to 22 centimetres across. After the dirt was wiped off, most of them still shone, and they showed old writing and symbols. Some carry four characters that mean home of prosperity. The objects show that wealthy Han people were buried here.
Two scholars argue that later mirror designs never matched the quality of mirrors from the Warring States period.
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