240 natural, fancy colored diamonds arranged in the shape of a butterfly. Photo by Robert Weldon/© GIA
The Butterfly of Peace is composed of 240 natural stones, weighing 167 carats and arranged in a symmetrical pattern of similar cuts and colors.

A chemically pure, perfect crystal of diamond is colorless. But natural diamonds exist in many colors, from warm reds and oranges to rich blues and violets; some are even milky white or solid black.

Flawed Crystals, Fancy Diamonds

These colored diamonds, called “fancy,” sometimes contain chemical impurities such as nitrogen, which gives diamonds yellow and brown tones. Defects in the crystal structure can also give a stone color—green diamonds, for example, often get their color this way. Natural fancy diamonds are rare and highly valued.

Diamonds That Glow

Some diamonds glow under ultraviolet (UV) light, a phenomenon known as fluorescence. Diamonds of all colors can fluoresce, and two similarly colored stones may appear very different under UV light.

Most diamonds do not fluoresce, but many in the Butterfly of Peace do.

Diamonds arranged in the shape of a butterfly.
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Robert Weldon/© GIA
Diamonds arranged in the shape of a butterfly.
Robert Weldon/© GIA
Photos by Robert Weldon/© GIA

Use the slider above to compare two views of the Butterfly of Peace, in natural light and under UV light. Can you spot the fluorescing diamonds? 

Look closely for:

  • Yellow diamonds that fluoresce yellow
  • Yellow diamonds that fluoresce lime-green
  • Pink diamonds that fluoresce blue
  • Gray-green diamond that fluoresce milky-white

See the Butterfly of Peace exhibit and other incredible gems and minerals in the Mignone Halls of Gems and Minerals.