Vintage Blue Opal Ring-Authentic or Imitation?

Hi everyone!....This is a one of many thrift purchases...for maybe $10 or less...its sterling silver...the small clear stones surrounding are I'm guessing are crystals....the large Blue stone in the center have flecks of light green, light blue, royal blue...and a darker blue or black in the background...then I discovered by accident that when the light is directly behind the ring all of the colors disappears and then the stone becomes transparent and sort of a dark pink....so that's amazing.....I'm not sure how old it is or if it is truly a Opal....so if someone knows.....please feel free to share your thoughts.....Thank you much

 

Probably glass. Not a real opal anyway. The one shot makes it looks like dragon's breath glass. A black opal that good would be in high-karat gold.

 

I think dragon's breath too.