Date: Western Han (206 BC - AD 8)
Dimensions: Diameter 7.4 cm
Weight: 50 g
Material: Bronze
Donated by Jin Gong
A light transmitting mirror is a special bronze mirror. Its surface can not only function as a mirror, reflecting people, but more importantly, when the sunlight or parallel light shines on the surface, the reflection and projection of the mirror will show the image of the characters and designs on the back of the mirror.
Two key points should be noted in casting the light transmitting bronze mirror: one is the cooling solidification process during the casting. When the bronze mirror is cooling quickly, the concave-convex decorative design of the back of the mirror will produce the corresponding slight unevenness on the surface in the solidification and shrinkage processes. The second is the grinding and polishing process, in which the surface comes up with new elastic deformation, further increasing the mirror undulation. Only when two conditions are met, can the ‘light transmitting’ effect be realized.
