Ring with Clear Blue Iridescent Stone

[phate008]

I have been trying to establish where this ring was made and what the stone is. It is sterling/14k gold. According to some things I read the "14ct" is mainly used in GB and Europe. All my jewelry I've had is either k or kt marks. The stone has properties that remind me of opal or moonstone. It has an iridescence in some light. It also looks see-through and bluish. There are a few stone that looked similar, but nothing that made me say "that's it". One of the closest was a pic of a blue moonstone. It may just be iridescent blue glass, but I wanted to get a firm answer. Any ideas on what kind of stone this may be or a guess as to where it was manufactured. The makers mark looks to be a S or a Swirl of some kind. Any help is appreciated. Thanks

 

Amazon Forum Fav 👍

A History of Mining on the Kenai Peninsula, Alaska - Grab it through Amazon!

[phate008]

Forgot to add one pic of the mark for reference. It is also mark 925 inside of band so it is sterling with gold accents.

 

[DDancer]

It looks rather porous for a gem stone, but I cant tell if I see chips or bubbles as well. Closer, clearer pictures in natural light may help~ or a local jeweler. Handsome, looks European to me.