It's something to do with the refraction of the light.
The luster of the real pearl is unique and depended on the reflection, refraction and diffraction of light on the translucent layers of the pearl.
Light- refraction for near-invisibility and sensors for constant medical feedback.
Sound effects such as absorption, reflection, refraction or interference are also studied by acoustics.
Some of the most common vision tests include visual acuity tests, refraction, visual field tests and color vision tests.
Without butterfly around the refraction will be not happen.
This gives each diamond an ideal set of proportions for optimal reflection and refraction of light.