corundum, synthetic corundum.7, gems

Gemological investigations of Tairus hydrothermal synthetic ruby revealed characteristic microscopic features, including solid alloy inclusions consisting mainly of copper–iron alloys and wavy growth lines. Chemical analysis by microprobe showed that the chromium concentration in the area of the growth lines averaged 3.81 wt.% Cr₂O₃, as compared to 1.53 wt.% Cr₂O₃ in the remainder of the stone. Characteristic infrared absorption peaks are 3308, 3233, and 3186 cm⁻¹.