Research Article
Gemological and Spectral Characteristics of Gem-Quality Blue Gahnite from Nigeria
Table 2
The EPMA test results of gahnite (wt%).
| Samples | Al2O3 | ZnO | FeO | Na2O | MgO | CoO | MnO | Cr2O3 | CuO | SiO2 | K2O | CaO | Total |
| S01 | 54.83 | 40.73 | 2.37 | 1.31 | 0.06 | 0.02 | 0.06 | 0.01 | 0.00 | 0.05 | 0.00 | 0.00 | 99.40 | S02 | 56.56 | 40.23 | 2.20 | 1.37 | 0.05 | 0.04 | 0.01 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 100.45 | S03 | 56.13 | 40.49 | 2.18 | 1.32 | 0.02 | 0.03 | 0.02 | 0.00 | 0.01 | 0.00 | 0.06 | 0.02 | 100.20 | S04 | 55.44 | 40.91 | 2.24 | 1.33 | 0.04 | 0.05 | 0.05 | 0.03 | 0.01 | 0.01 | 0.00 | 0.00 | 100.07 | S05 | 55.98 | 40.72 | 2.26 | 1.40 | 0.05 | 0.03 | 0.07 | 0.04 | 0.00 | 0.05 | 0.00 | 0.04 | 100.54 | S06 | 56.06 | 40.34 | 2.22 | 1.32 | 0.03 | 0.03 | 0.09 | 0.00 | 0.00 | 0.03 | 0.00 | 0.00 | 100.10 | S07 | 55.28 | 40.64 | 2.16 | 1.61 | 0.01 | 0.10 | 0.03 | 0.06 | 0.07 | 0.03 | 0.02 | 0.00 | 99.89 | S08 | 55.44 | 40.48 | 2.59 | 1.33 | 0.04 | 0.02 | 0.09 | 0.02 | 0.04 | 0.01 | 0.00 | 0.00 | 100.01 | S09 | 55.14 | 39.66 | 2.69 | 1.33 | 0.06 | 0.05 | 0.02 | 0.07 | 0.02 | 0.01 | 0.00 | 0.05 | 99.02 | S10 | 55.19 | 40.76 | 2.00 | 1.18 | 0.03 | 0.05 | 0.03 | 0.04 | 0.00 | 0.00 | 0.01 | 0.00 | 99.28 | S11 | 55.94 | 39.74 | 2.32 | 1.49 | 0.00 | 0.02 | 0.01 | 0.03 | 0.04 | 0.00 | 0.03 | 0.02 | 99.55 | S12 | 55.55 | 40.95 | 2.11 | 1.27 | 0.03 | 0.03 | 0.03 | 0.00 | 0.04 | 0.02 | 0.01 | 0.00 | 99.97 | S13 | 55.78 | 40.62 | 2.31 | 1.34 | 0.05 | 0.07 | 0.05 | 0.01 | 0.00 | 0.01 | 0.00 | 0.01 | 100.22 | S14 | 55.74 | 39.48 | 2.09 | 1.57 | 0.03 | 0.06 | 0.00 | 0.03 | 0.00 | 0.00 | 0.01 | 0.00 | 99.00 | S15 | 55.47 | 39.07 | 3.23 | 1.30 | 0.10 | 0.04 | 0.05 | 0.08 | 0.04 | 0.02 | 0.00 | 0.00 | 99.34 | Average | 55.64 | 40.32 | 2.33 | 1.36 | 0.04 | 0.04 | 0.04 | 0.03 | 0.02 | 0.02 | 0.01 | 0.01 | 99.80 |
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