Oxide

Volcanic ash (wt%)

SiO₂

67.56

TiO₂

0.33

Al₂O₃

12.48

Fe₂O₃

1.06

MnO

0.054

MgO

1.51

CaO

4.15

Na₂O

1.95

K₂O

2.31

P₂O₅

0.12

SO₃

0.45

E.C.

7.27

Total

99.24