Table 1 Analytical results (wt%) obtained by EDS spectrometry on crystals observed on the glaze surface and cross-section by SEM.

Spectrum1 (Hematite)

Figure 3c

4.1

25.7

0.8

1.6

4.9

12.4

0.9

1.5

1.2

1.5

45.3

0.3

Spectrum2

Figure 3d

5.5

34.3

0.4

2.3

11.8

33.5

3.2

3.7

1.1

1.1

2.6

0.6

Spectrum3

Figure 4d

6.3

31.5

0.7

1.8

8.5

19.4

1.2

1.3

1.8

3.2

24.4

0.6

Spectrum4

Figure 4e

5.0

37.2

0.8

1.0

9.9

32.4

3.1

3.5

0.7

0.7

6.1

0.4

Spectrum5 (Hematite)

Figure 4g

4.2

28.0

0.5

1.6

3.1

3.8

0.8

0.5

3.2

1.3

52.8

0.8

Spectrum6

Figure 4h

4.2

36.6

0.7

1.7

9.4

35.4

2.5

3.8

0.9

0.6

4.7

0.2

Spectrum7 (Anorthite)

Figure 4j

4.6

21.1

0.7

2.4

15.1

30.4

1.3

19.2

1.5

1.0

1.9

1.0

Spectrum8 (Zircon)

Figure 4n

5.3

12.7

0.3

1.0

4.5

24.6

1.8

2.7

1.8

2.6

2.3

40.6

Spectrum9 (Hematite)

Figure 5c

4.0

29.1

0.7

1.9

6.4

20.6

1.2

1.1

1.3

1.8

31.8

0.2

Spectrum10 (Hematite)

Figure 5e

5.1

31.8

0.5

1.2

7.8

17.7

1.6

1.2

1.4

0.1

30.3

0.4

Spectrum11 (Luogufengite)

Figure 5g

6.8

28.3

0.4

0.8

6.2

20.3

1.8

1.7

0.9

0.2

32.5

0.4

Spectrum12 (Hematite)

Figure 6f

6.7

28.2

0.6

1.3

5.1

20.1

0.9

1.0

1.6

0.3

33.9

0.4

Spectrum13 (Zircon)

Figure 6h

5.7

30.7

0.2

0.8

2.7

16.8

0.2

0.3

0.9

0.4

1.0

41.4