Characterization of Red, Pink, Orange, and Purple Gem-Quality...
A round crystal in Vietnamese spinel V-5 (Figure 7c) was selected for Raman anal- ysis (Figure 13). As shown in Figure 13b, V-5 has titanite absorption peaks of 163 cm−1, 254 cm−1, 318 cm−1, 335 cm−1, 468 cm−1, 552 cm−1, 612 cm−1, ...