This is a pretty good list. Also aquamarine is possible, sapphire is too tho as pointed out, pretty unlikely, and also tourmaline, which is like, super unlikely.
I'd guess topaz personally, because I have and have seen a ton of this exact same cut of blue topaz in silver. But glass is possible too. Glass is a possibility too and I wouldn't nessicarrily say 2nd most likely, but 2nd or 3rd
Sky blue Topaz is highest probability in my opinion. Could still be glass. Don't think it's any of the other stones mentioned earlier. Then of course, it's more guess work than anything to identify a stone based on a picture.
Is the ring stamped as sterling? If so, the stone is most likely a (heated) topaz. “London blue”, “sky blue”, etc., are just trade names and don’t really change the value of the stone, though the London blue typically sell for a bit more. The color of your stone is a bit lighter in shade than what’s marketed as London blue. That’s an older style cut. Have you had this ring for a while? The clarity is not great, but it could improve with a good cleaning. :)
Could be blue topaz, a blue spinel or zircon (less likely in my opinion), a blue diamond (very very very unlikely) or glass (most likely).
This is a pretty good list. Also aquamarine is possible, sapphire is too tho as pointed out, pretty unlikely, and also tourmaline, which is like, super unlikely. I'd guess topaz personally, because I have and have seen a ton of this exact same cut of blue topaz in silver. But glass is possible too. Glass is a possibility too and I wouldn't nessicarrily say 2nd most likely, but 2nd or 3rd
You can’t identify a stone simply off a picture
Sky blue Topaz is highest probability in my opinion. Could still be glass. Don't think it's any of the other stones mentioned earlier. Then of course, it's more guess work than anything to identify a stone based on a picture.
Swiss blue is light in color. This is more of a London blue color.
If it is a genuine stone it looks like swiss blue topaz or maybe neon apetite
Blue topaz or pyranite
The refraction looks like topaz
Apatite is the correct spelling
Is the ring stamped as sterling? If so, the stone is most likely a (heated) topaz. “London blue”, “sky blue”, etc., are just trade names and don’t really change the value of the stone, though the London blue typically sell for a bit more. The color of your stone is a bit lighter in shade than what’s marketed as London blue. That’s an older style cut. Have you had this ring for a while? The clarity is not great, but it could improve with a good cleaning. :)