Table 2.

Element analysis of four points in Figure 9.

Point	Oxygen		Aluminum		Silicon		Phosphorus		Calcium		Ferrum
	wt.%	at.%	wt.%	at.%	wt.%	at.%	wt.%	at.%	wt.%	at.%	wt.%	at.%
1	23.51	41.16	0.33	0.34	19.21	19.16	1.62	1.46	51.34	35.88	3.99	2.00
2	23.45	41.02	0.07	0.07	19.43	19.36	2.27	2.05	50.93	35.57	3.86	1.93
3	23.47	41.10	0.06	0.07	18.92	18.87	1.96	1.77	52.20	36.49	3.39	1.70
4	24.41	42.29	0.13	0.13	18.97	18.72	2.12	1.90	51.08	35.33	3.30	1.64