Aquamarine is my guess.
How can I rule out glass?
Refractive Index using a refractometer perhaps?
DK
With only a loupe? Lol
Do you know is it 10K or 14K? If it's not 14K, all bets are off. Most seem like they were 10K.
Its really pretry
What are you going to do with it ?
Wear it as is ?
Or a conversion?
Or will it depend if its real or not ?
It also could be synthetic spinel too, right?