Element

Weight (%)

Oxygen (O)

36.28

Aluminum (Al)

0.72

Silicon (Si)

26.59

Potassium (K)

0.55

Calcium (Ca)

3.5

Zinc (Zn)

29.16

Sodium (Na)

1.06

Magnesium (Mg)

2.14

Table 8: Elemental composition.