Oxide

Shale

Syenite

SCO-1 (pressed pellets) (Saini et al., 2002)

GSR-5 (fine powder)

STM-1 (pressed pellets) (Saini et al., 2002)

GSR-7 (fine powder)

Certified Value (%)

Deviation (%)

Certified Value (%)

Deviation (%)

Certified Value (%)

Al₂O₃

13.6

−7.5

−33.2

18.82

18.5

−3.5

−38.5

17.72

SiO₂

62.6

2.7

−9.4

59.23

59.6

2.0

−16.4

54.48

P₂O₅

0.23

13.0

12.5

0.16

0.16

18.8

−

0.018

K₂O

2.75

−3.3

−1.4

4.16

4.3

1.9

−3.7

7.48

CaO

2.61

−10.3

3.3

0.6

1.1

−3.6

−6.5

1.39

MnO

0.05

−40.0

19

0.02

0.23

−4.3

12.4

0.12

Fe₂O₃

5.14

−8.4

15.9

0.00076

5.21

−6.3

−11.9

6.04