Why Does the Dirt Shine?

From The Old Mermaids Book of Days and Nights for today's date:

“Why does the dirt shine?” Lily asked.

Myla smiled. The Church of the Old Mermaids had no dogma, but Myla did adhere to at least one golden rule: Answer all questions put to her by a five-year-old child with honesty and beauty.

“Well, Lily my Lily,” Myla said, “I can’t be sure, but I think those shiny bits of sand are star dust—at least that’s what Mother Star Stupendous Mermaid told the other Old Mermaids when they first got to the New Desert. They had to sleep in the wash for a while, and Mother Star Stupendous Mermaid told them the sand would keep them warm and give them good dreams because it was made from star dust, shed by the stars the way we shed skin. I’m not sure the Old Mermaids believed her, but they did agree that the star dust was much more comfortable to sleep on than they would have guessed.”

—An Old Mermaid Sanctuary