Tetragonal mineral such as jacinth or jargoon (6)

I believe the answer is:

zircon

(Other definitions for zircon that I've seen before include "jargoon?" , "'Hard mineral, semi-precious gemstone (6)'" , "Mineral used as a gemstone in its transparent form" , "Tetragonal mineral" , "Crystal-like semi-precious stone" .)

I've seen this clue in The Telegraph.

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.