Table 3.

Elemental composition of specimens measured by EDS (%).

Specimen Name	O	Si	Ca	Fe
A1	51.16	2.42	3.75	42.66
A2	35.12	1.32	4.82	58.74
B1	39.88	1.01	8.22	50.88
B2	38.51	3.46	8.90	49.13