Help identifying this stone

Hi,
I have a customer requesting the custom order ring to be similar of previous engagement ring, she says it was a moonstone. Sent me this picture. I have not seen any moonstones similar to this, can anybody help me figure out what exactly it is?
Thanks so much:-)

Hi, I have copied and pasted several images of blue moonstone from google
and put on the same page as your photo, I believe it quite possibly is blue moonstone see attached
hope this helps

https://gemsociety.org/wp-content/uploads/2015/09/Blue-moonstone.docx

The play of the blue tones let m think in th direction of a iolith. I may be wrong but I doubt it.

Okay happyduck I would have thought that if the clarity of the iolite was good it would have been faceted not a cabochon.
it is very difficult to identify a gem from a photo

My customer said that this was her engagement ring that it got stolen, so I asked her what The ring was listed as but I didn’t get a response other then she thought it was a Moonstone.
Still am not really feeling the moonstone idea just because I really never seen a moonstone to look exactly like that. Or really anything very similar. I’m thinking it’s kyanite…?

If the customer believes it was moonstone then give her a moonstone ring
I would think she would be happy with that
just my thought on the matter
cheers