Flaky rock

I think it could be either:

Which length description are you looking for?:

mica

'flaky rock' is the definition.
(I've seen this in another clue)

This is the entire clue.

(Other definitions for mica that I've seen before include "Semitransparent insulating mineral" , "Shiny silicate mineral" , "Muscovite with perfect cleavage" , "Transparent mineral" , "Isinglass" .)

I've seen this clue in The New York Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.