Glass ingredient (4)

I believe the answer is:

sand

(Other definitions for sand that I've seen before include "It's used to make glass" , "Hourglass particles" , "Grains by the sea" , "Shore grains" , "Result of rock erosion" .)

I've seen this clue in The Times and The Sunday 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.