gems, corundum, history.1, spinel, beryl, emerald

Vauquelin reports chemical analyses of spinel ruby and emerald from Peru. His investigation of spinel distinguishes its composition from that of true ruby, while the emerald analysis is historically important for the identification of a previously unknown constituent, later named beryllium (beryllia as the oxide). The paper represents an important early application of quantitative chemical analysis to gemstones and contributed to the mineralogical distinction of visually similar gem materials.