Composition

Center edge

Na2O

0.07

0.02

0.02

0.07

0.02

0.00

0.02

0.02

0.00

0.00

FeO

27.80

28.31

28.70

28.72

30.14

29.61

30.52

31.16

29.39

33.04

K2O

0.00

0.00

0.00

0.00

0.00

0.01

0.02

0.00

0.00

0.02

SiO2

36.99

36.91

37.04

36.94

36.94

36.66

37.01

36.92

35.63

37.18

MnO

8.02

7.66

7.65

7.25

6.92

6.65

5.35

3.43

2.22

0.90

MgO

1.27

1.28

1.33

1.36

1.47

1.45

1.50

1.64

1.68

2.09

CaO

3.81

3.98

3.94

4.06

4.14

3.99

3.86

3.91

5.02

5.28

Al2O3

20.81

21.07

21.24

21.17

21.17

20.97

21.19

20.90

21.24

21.38

Total

98.78

99.27

99.95

99.57

100.82

99.34

99.47

97.98

95.21

99.92

Na

0.02

0.01

0.01

0.02

0.01

0.00

0.01

0.01

0.00

0.00

Fe

3.80

3.86

3.88

3.90

4.06

4.04

4.14

4.27

4.12

4.44

K

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

Si

6.05

6.01

5.99

5.99

5.95

5.98

6.00

6.05

5.97

5.97

Mn

1.11

1.06

1.05

1.00

0.94

0.92

0.73

0.48

0.31

0.12

Mg

0.31

0.31

0.32

0.33

0.35

0.35

0.36

0.40

0.42

0.50

Ca

0.67

0.69

0.68

0.71

0.71

0.70

0.67

0.69

0.90

0.91

Al

4.01

4.04

4.05

4.05

4.02

4.03

4.05

4.04

4.20

4.05

Total

15.96

16.01

16.00

15.99

16.05

16.01

15.98

15.93

15.95

16.01