Important Explorations on Surface Corrosion of the Copper Coins Sourced from the Qing Dynasty

Table 2

Mass fractions of main elements in the corrosion products on the surfaces of coins produced during the Qing Dynasty.

Copper coins	Elemental mass fractions (wt.%)
	Cu	Sn	O	Si	C	Al	Pb	Ca	Fe	Pd
Kx-TB	22.44	1.08	40.64	10.04	19.53	3.77	—	2.48	—	0.02
Jq-TB	9.28	2.23	39.19	11.49	21.14	5.05	3.92	1.74	5.97	—
Dg-TB	39.10	2.75	34.09	5.63	18.42	—	—	—	—	0.01
Tz-TB	20.79	5.37	43.71	19.66	—	5.98	4.50	—	—	—
Ql-TB	19.03	11.82	32.15	9.18	21.65	3.53	1.01	1.63	—	—