Presidium gem tester surprise

[RMOO]

A while back I purchased this ring at an estate sale for $10, just for fun, because my favorite color is purple. I have a real amethyst set in yellow gold, and I thought this would give me a white metal option, plus the stone is sizable. It is stamped "sterling" and either CI or CZ (It looks more like CI, but it would make more sense if it was CZ.) Fast forward to last week, when I purchased a Presidium gem tester and was testing my real jewelry and some fashion rings also purchased at rummage/estate sales. As I expected, the fashion stones that are supposed to look like diamonds tested as glass, no shock there. But I was surprised that this pear tested as amethyst (I was expecting more glass. I know amethyst is inexpensive, but I also googled that there exists lab amethyst. The ring is now tight on the desired finger, so my quandary is this: (1) IF it is genuine, then I wouldn't mind spending a little cash resetting it in a white gold bezel or prong solitaire, nothing fancy (2) if it is a lab, I don't want to look like a dope taking it to a gemologist and spending cash on an evaluation. So, how likely do you think it is, that is could be a real amethyst?

 

[Daisys and Diamonds]

What a lovelly colour and what a lovelly surprise
I wish amethyst got more love

back when it was less common it was much more exspensive- a lot of royal families have fabulous old pieces

If its a genuine stone why not give it a new home !

Unfortunately in my country its sold down the mall in unimaginative and usually unattractive cheaper settings

 

[Daisys and Diamonds]

What is the ring made off ?
Edited to say opps you said stirling

Even if it is lab, its a pretty ring and wont cost much to get the ring sized

its too pretty not to be worn

In the present economy a lot of benches should be greatful for the work, my jewler in town would be happy to size it for you and not care that some of it is glass !
Im sure a local to you jewler would size this for you