ELI5: Is the Pearl in Girl with a Pearl Earring Real?

The pearl in the famous painting is not real; it is an imaginary piece of costume jewelry created by the artist.

To understand why, think about playing dress-up at home. When you put on a plastic crown, you pretend to be royalty, but the crown is just a toy. The artist, Johannes Vermeer, did something very similar. He was not painting a rich princess wearing a fortune in diamonds, but a made-up character wearing fancy-looking props.

Here is why that shiny earring could not be a real pearl in everyday life:

• It is way too big: In nature, pearls grow slowly inside oyster shells. A real pearl the size of the one in the painting would be as big as a bird's egg. Back then, a pearl that large would have cost more than an entire street of houses, and only the richest kings could ever hope to see one.
• It is far too shiny: Real pearls have a soft, milky glow. The earring in the picture has a bright, sharp gleam on it, like a Christmas tree ornament or a drop of water.
• It was likely fake glass or metal: People in Vermeer's time often wore cheap, imitation jewelry made of varnished glass or polished tin to look fancy for special events, just like the costume jewelry people buy at the mall today.
• It is just an optical illusion: If you walk up very close to the painting, the pearl disappears. Vermeer only painted two quick dabs of white paint: one bright spot at the top reflecting light, and a soft glow at the bottom reflecting her white collar. Your brain connects those spots and tricks you into seeing a heavy, shiny ball.