Ming Dynasty
Excavated from a Ming tomb at the construction site of Changzheng Pharmaceuticals, Leshan, in 1972. Convex lens, crystal. D:4.1 cm, t: 0.15 cm. When unearthed, the lens was in a corroded metal frame which could not be conserved. (Collection of Wuyou Administration Bureau, Dafu [Great Buddha], Leshan City.)
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