Component

Percent by weight

Component

Percent by weight

SiO2

38 - 46

Fe2O3

6 - 13

Al2O3

10 - 16

TiO2

1 - 3

MgO

16 - 35

H2O

8 - 16

CaO

1 - 5

Other

0.2 - 1.2

K2O

1 - 6