I've been working at it ever since. It is still not done, but barring any unforeseen eventualities like the stone shattering (may it not come to pass), the ring is now within sight of completion. It is at this precise stage that I should have written, "I think I'll cast it in silver and set the stone in the silver version." Grrrr.
Instead, my hands look as though I've been coal mining, the ring isn't finished, and neither is my term paper on Italian Sociolinguistics. And who can write an academic paper with fingernails like these?
Here are some photos of the work in progress. I've still got some work to do, mostly on the strands that connect the band to the bezel, but chances are I will get it finished this week. I'm still not sure what the stone is, but it's possibly ammolite: time - and Tamas - will tell.