Blister triangular pearl 25x25 mm, this iridescent shell color gray dune shows the colors popular of the rainbow

This piece of shell with pearl is called blister.
It's a beautiful glossy piece with a sunset theme.
The colors of the rainbow are present.
These colors are the result of the popular phenomenon of color dispersion.
The section of the pearl is partially gray, partially white.
This iridescent shell measures 25 mm.
Photos taken under LED lighting.