Post about true events in your life where you ask the question “Am I the asshole in this situation?”
Thing is, star opal isn't... real.
The GIA seems to differ. They're rare, but they're definitely real, and they've been found in Thailand.
On balance you're very probably correct that her ring isn't star opal simply because of how rare they are, but still, slight YTA for jumping to conclusions immediately without taking a look at the stone first.
@Destructdisc I'm making two separate comments because I realized I'm coming off as defensive and possibly aggressive. FWIW, I did spend about an hour after talking to her combing the internet (including that article) for anything that looked like what she showed me. I was trying to keep in short in the post, but I realize my words were reductive and not useful for communicating my thought process.
@BabushkaCat No worries, it's all good, gemology and materials science is so fucking cool and I'm really delighted you're studying it
@Destructdisc
"It may also display asterism, though star opal has only been reported from Idaho."
Me: "Thing is, star opal isn't... real. Not in the same way that you see star sapphires."
I was saying the same thing. The asterism in her "star opal" looked like a star sapphire, not one that you would see on a star opal. It also doesn't say in the article that it comes from Thailand?
ETA: I didn't get into the long bits in the post, but the stone on her gem was actually a cat's eye that split into different rays in the sun (which happens when cat's-eyes get hit with two different points of light.) Cat's-eye opal definitely exists for sure, but it comes in a kinda yellowish green to orange (brown), not very light blue.
@BabushkaCat Oh yeah no definitely, star sapphires are like that because of crystal structure, star opals are like that because of impurities. Totally on the same page here. I'm glad we could come to an understanding :D
NTA
You could also suggest she gets it appraised and insured. That way she'll hear the news from a pro not so close to her.
This might be the way to get her to listen: suggest that if it is what she says, it's so rare that it should be insured by a reputable insurance company.
@BabushkaCat NTA Im in a profession involving science, where there are a lot of dupes claiming to be science (think medicine vs. homeopathy, its something similar to that), so believe me, I get you. Lots of people like to ask me what I think of the service they are paying for... and then get mad when I tell them its a scam lol. And Im like, dude, I just saved you from wasting money for the years to come.
Some people just want to hear they are right, I dont think that should stop us from being honest (especially to loved ones!), especially when they are asking for an opinion in the first place.