Artificial coloration of ancient agate beads: a mineralogical study

Heritage Science

Table 2 Chemical compositions of the different color zones

[norm. at.%] Sample zone	Si	O	Na	K	Ca	Fe
A Dark red zone	35.9	63.5	0.36	0.05	0.08	0.03
A Scattered white zone	35.8	63.3	0.68	0.05	0.22	0.03
B Black zone	35.9	63.6	0.38	0.07	0.06	0.03
B Scattered white zone	35.7	63.2	0.75	0.08	0.19	0.03
F Red zone	35.9	63.4	0.39	0.08	0.11	0.04
F Scattered white zone	35.9	63.4	0.35	0.09	0.16	0.04
E Red zone	35.98	63.54	0.32	0.05	0.06	0.04
E Scattered white zone	35.85	63.28	0.59	0.07	0.17	0.04
H Red zone	35.88	63.68	0.28	0.05	0.07	0.04