Research Article
Gemological and Spectral Characteristics of Gem-Quality Blue Gahnite from Nigeria
Table 5
Comparison of different Cr3+-activated spinel photoluminescence spectra (650∼750 nm) (nm).
| Species | 650∼680 | 680∼690 | 690∼702 | 702∼712 | 712∼725 | Source |
| Natural gahnite | 675.3 | 686.3 (R) | 693.8, 697.9 | 708.5 | 717.6 | This work | Natural spinel | 672, 674, 675 | 685.6 (R), 686, 687, 689 | 695, 698, 700 | 705, 707, 709 | 717, 722 | [21] | Natural spinel | 677 | 685 (R) | 697 | 710 | 718 | [19] | Natural spinel | 666, 676 | 686 (R) | 698 | 708 | 717, 723 | [23] |
| Identification | | R/N-line | R-PSB | |
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