| No. | Samples | Fluorine | Possible Mg |
| 1 | SARM 18 (Coal) | 148 ± 47 ppm | Mg |
| 2 | SARM 19 (Coal) | 224 ± 37 ppm | Mg |
| 3 | SARM 20 (Coal) | 235 ± 57 ppm | Mg |
| 4 | NBS 91 (Opalglass) | 5.75% ± 0.034% |
|
| 5 | NBS 694 (phosphate-rocks) | 3.24% ± 0.029% |
|