Hmm, that cubic zirconium is often associated with dating? ;’)
gotcha!
I tried reading up on that, very very complicated. I was wondering if zircons didn’t simply land here when the comet/meteor hit the earth...and that wouldn’t date the impact site, would it? But it seems that, although some extra-terrestrial object do contain zircons, when the body hits terra-firma, the zircons fracture.
And I’m really still no wiser...