This is from TOS: By Any Other Name. Zamata described the circumstances a bit more clearly in this interview
ZAMATA: ...Captain Kirk was flirting with this alien princess, as he does. And he gave her a rose. And she goes, oh, we have something like this on my planet except it's made out of crystal and it's called Sasheer. And my parents were like yes...
And we can see the correct spelling in the Blish novelisation of the episode (based on the original script).
“Flowers,” he said, moving closer to her, cautiously. “I don’t know the variety.”
“Our memory tapes tell us of such things on Kelva,” Rojan said.
“Crystals which form with such rapidity that they seem to grow. They look like these; fragile things, somewhat. We call them ‘sahsheer.’”
Star Trek 6: By Any Other Name
Interestingly sahsheer crystals receive a name-check in the EU novel Aftermath despite being native to another galaxy.
“That’s the part of war people don’t talk about much. Sure, the loss of life is horrible—the Breen took a lot of my friends that day. And the property losses, okay, those are bad too. But it’s a damn sight easier to rebuild a lecture hall or an office complex than it is to regrow a Gordian oak or a sahsheer crystal."