Parameter

index

1

2

3

4

5

Relative Density

35-37

39-41

44-46

39-41

50-52

Na2O

7% min

8.2% min

10.2% min

9.5% min

12.8% min

SiO2

24.6% min

26% min

25.7% min

22.1% min

29.2% min

M

3.5-3.7

3.1-3.4

2.6-2.9

2.2-2.5

2.2-2.5

Fe

0.02% max

Water Insoluble

0.2% max