Corundum var. Sapphire and Ruby

Corundum var. Sapphire/Ruby

Zazafotsy Quarry, Madagascar

Fluorescent 

The finer varieties of Corundum are the gemstones sapphire and ruby. Corundum in its pure state is colorless, but the presence of small amounts of impurities can impart a broad range of hues to the mineral. Ruby owes its red color to chromium, sapphire its blue shades to the presence of iron and titanium.