Suddenly I felt a shimmer in my magic, like sunlight glancing off water. This time I didn't care if Rosethorn rode on without me. "Mica!" I yelled and jumped off my horse. "There's sheet mica here!"
Mica lay scattered over a heap of rocks that had tumbled from a cliff face. It lay to the right of the road in sheets of a single thickness, delicate amber-colored glass that would chip away at a breath, and in clumps of different sizes, some of a hundred sheets or more. I picked up a few thick clumps to keep.
"You like this stuff?" Jayat had followed me. "What's it good for?"
"Scrying, if you need to have a use for everything." I showed him glittering flakes that fell from my hand like snow. "But mostly it's just wonderful — so delicate, and yet it's stone."
I flicked a tiny burst of magic up the slope. Flakes, sheets, and clumps of mica flashed, thousands of flat crystals in the sun. Everyone who rode by would now see the stone as I did, glittering in the light.
"Beautiful." Jayat liked what I had done. "I never thought of it like that. It was always just glassy stuff, laying around."
Luvo looked at Jayat. "That is what magic is for, Jayatin. To help us think of the world in new ways."
- Tamora Pierce, Melting Stones
Hurray, mica! Mica is particularly resonant for me, living in this city with the Wissahickon Valley and its miles of glimmering trails... This quote is from Tamora Pierce's newest book in the Circle of Magic world -- which is particularly noteworthy for having been released first in full cast audio format, a year before its release in print.