09/30/2026
What makes a sapphire blue, yellow, pink, or nearly any other color?
It all comes down to chemistry.
Pure corundum is colorless, but trace elements and defects within its crystal structure can interact with light and produce the remarkable range of colors found in natural sapphires and rubies.
GIA researchers have taken a closer look at exactly how these microscopic chemical differences affect the color we see in corundum. Their research examines the specific elements responsible for different colors and the relationship between their concentrations and the resulting color.
It’s a fascinating look at the science behind one of the most colorful groups of gemstones.
Read GIA’s full article to learn more about what’s happening inside corundum at the atomic level.
