Without the weight of the ring, it is impossible to guess at approximate melt value of the gold.
The diamonds have to be tested to verify if they are real.
Your best bet is to go to 2 or 3 different jewelers to see if they will give you a free evaluation.
I would guesstimate,
$3oo to $4oo
Look around to see if you can find similar style ring.
But see a jeweller,
And if you find rings that's set with real stones, and plan to scrap the gold only, always have your stones removed, and save all of them.
If not your just giving up lots of $$$$
I have the gold made into one once bars, when I have enough, and the stones cleaned and graded, and appraised, I have 4 one once bars,
And stones valued at $7,000
In a safety deposit box.
Jmo