Color Types for Color Change Gemstone
A brief description of the color types for color-changed sapphire used at AGL Thai Laboratory Gemology.
As color-change sapphire, exhibits different colors in different light. Color change sapphires are blue in outdoor light (daylight) and purple under incandescent or pink to reddish-violet in incandescent light. Color change sapphires come from a variety of locations, including Thailand and Tanzania. The color-change effect is caused by the interaction of the sapphire, which absorbs specific wavelengths of light, and the light-source, whose spectral output varies depending upon the illuminant. Transition-metal impurities in the sapphire, such as chromium and vanadium, are responsible for the color change.
Explanation of color and % Color Change for Alexandrite Colorchange % Approximately trenslates to:
|Excellent||80% to up Easily change, Exthrenely Strong|
|Strong||60% to 70% Change Easily|
|Moderate||40% to 59% Moderate-Apparent Color-Change|
|Slightly||20% to 39 Subtle Color-Change|