Price check on opal it looks like ring by Walter R Thomas.

[BrokenStarGal]

 

[Bron357]

The value of the ring will depend upon the assay of the metal and the quality of the opal. If the ring is hallmarked for a reknown and desirable maker, that can add to the value.
From the photo the ring metal appears to be, Im guessing here, tarnished or blackened sterling silver. The opal appears to be white opal. A sterling silver ring with a small opal is worth around $50. If the metal is say 14kt gold, the value would be more (depending on the weight) so maybe a few hundred.
Opals are valued on their type and colour play. White opal is the least valuable. The value increases depending on how many different colours show, how vivid the colours are and how much of the opal “shows colour”.

 

[Daisys and Diamonds]

i love a pinky ring regardless of worth
its got a mythical kind of dark fairy tale look about it

opals are hard to photograph
do you get any colour play in the stone ?