Spot No.

1

2

3

4

Major oxides wt% recalculated to 100%

SiO₂

51.64

48.09

51.75

50.62

TiO₂

0.04

0.00

0.04

0.03

Al₂O₃

28.90

31.24

30.07

31.48

FeO*

0.47

0.27

0.38

0.45

MgO

0.08

0.21

0.16

0.12

CaO

13.65

16.45

13.12

12.45

Na₂O

5.01

3.57

4.29

4.65

K₂O

0.21

0.17

0.19

0.20

Total

100

100

100

100

Cations on basis of 8 oxygens

Si

9.55

8.89

9.25

9.42

Al

6.32

6.93

0.67

6.55

Fe

0.079

0.047

0.083

0.031

Mg

0.072

0.085

0.099

0.051

Ca

1.476

0.953

1.47

1.50

Na

2.37

3.32

2.64

2.68

K

0.039

0.04

0.035

0.027

An

62.45

72.72

69.28

65.70

Ab

36.30

21.99

29.58

33.10

Or

1.24

0.96

1.13

1.70