Table 2.

The results of SEM-EDS analysis.

Sample	Element content (%)
	C	O	Hg	As	S	Al	Pt	Si	Sb
R-Black	71.40	27.44				0.11	1.05
YZ	11.17	5.16	45.03		34.13	0.35		4.16
R-Red	63.85	25.31	5.14		2.97	0.17	0.95	1.61
SH	10.89	6.99		49.18	28.28	0.36		3.78	0.52
R-Yellow	69.54	22.61		3.40	1.88	0.23	0.87	1.28	0.19