Stunning video captured a rainbow in the clouds over Ribeirao Claro, Brazil, in a meteorological phenomenon known as cloud iridescence.

Iridescence like this happens when the clouds are very thin and are made of similar-sized water droplets.

The meteorological phenomenon, known as cloud iridescence, was seen above Ribeirao Claro, Brazil.(Andre Nassif) The meteorological phenomenon, known as cloud iridescence, was seen above Ribeirao Claro, Brazil.
The meteorological phenomenon, known as cloud iridescence, was seen above Ribeirao Claro, Brazil.(Andre Nassif) The meteorological phenomenon, known as cloud iridescence, was seen above Ribeirao Claro, Brazil.

What you’re seeing, essentially, is part of a corona -- when a rainbow-like halo engulfs the sun or the moon -- and the bands and colors change as the cloud evolves.

The meteorological phenomenon, known as cloud iridescence, was seen above Ribeirao Claro, Brazil.(Andre Nassif) The meteorological phenomenon, known as cloud iridescence, was seen above Ribeirao Claro, Brazil.

Iridescence is most often seen close to the sun.

It's usually spotted when part of a cloud is forming because that's when all of the water droplets have a similar history and similar size.