Variable Cobalt Doped Sapphire

In the sapphire crystal lattice, the chromophore cobalt demonstrates two distinct valence states: Co2+ (resulting in a blue coloration) and Co3+ (yielding a green hue), contingent upon factors such as temperature, atmospheric conditions, and growth parameters. The resultant coloration can span a spectrum from green to teal to blue, contingent upon the relative abundance of Co2+ and Co3+. These crystals consistently exhibit color variegations, primarily stemming from the intricate challenge of precisely controlling all growth conditions, thereby bestowing upon each gem a distinct and unique hue.

This material exhibits a notably inconsistent texture akin to the majority of cobalt-doped flame-fusion sapphires. Its provenance remains uncertain. The boules are characterized by their substantial size, typically displaying a predominantly pale green-yellow hue. However, a limited selection of sections can be to reveal an exquisite light blue-green colored gemstone.