But let’s be a bit more specific. What gives gemstones colors, or rather, what changes the way they absorb and reflect light so that they come out in so many different, striking colors?

While topaz normally ranges from clear to golden yellow to brownish yellow in color, the gem also has a green variety. The green color is caused by chromium or vanadium coloring a clear topaz stone, ...

Gemstones, including rubies, emeralds, and sapphires, can be sold for cash, much the same as diamonds and other jewelry.

The phenomenon by which bodycolor varies with a gemstone’s thickness is called the Usambara effect. Liu et al. (1999a) determined that this color variation is caused by the hue angle change ...

Beyond traditional cutting and polishing, however, gems can often be treated in ways meant to alter their color or clarity. In addition to enhancing their appearance, the process may also improve (or ...

A garnet's color depends on its chemical composition, according tothe International Gem Society. For instance, almandine garnets range from deep red to purple. While andradite garnets can be ...