From: A study on ancient casting method via microstructures of impurities and copper found in bronze excavated from the Unified Silla Period (7th to 10th centuries)
Cu
Sn
Au
Pb
Large robe front
87.7
10.1
2.0
–
Large robe inside
92.6
5.6
1.8
Small robe front
73.4
4.9
21.7
-
Small robe inside
77.8
13.8
8.4