I'm 99% positive that this ring is Jet and possibly whitby jet. A small black dome ring with the wood showing through from the inside of the dome. The exposed wood looks very much like the raw jet that I've seen.
I'd love to hear some other opinions on this....and obviously, I'd love to hear that it is Jet. To compare the wood on the ring to the raw wood, go to ...and scroll to the very bottom of the page
here is a site that gives "tests"
Great link Valerie, thank you so much!
I have a few rings like these (must dig them out now) -- with what looks like wood (even a coconut 'wood) with silver inlay.
I don't believe that they're jet, simply because of their shape and jet's fragility but definitely looking into some more. Could be carved horn to imitate tortoise, but that's a guess.
Here's another link from Morning Glory Antiques that I found very interesting and helpful, she also has a book listed from a woman in England who's an expert on jet ("Jet" by Helen Muller) at $12.50, I think this book is well worth the investment.
(scroll down about 1/2 of the way for the differences in Jet, Bog Oak, Vulcanite and Horn but the whole page is a great read)...the link for the book is at the bottom of the page
The feel of the wood on the inside was definitely not coconut and matched the grain in pics on the Morning Glory site, referenced above and it passed all of the tests on the site that Valerie referenced...but that being said, until one is really an expert it's hard to say for certain. Most of the items that I purchased with this ring were from the 1890's to the 1930s, so I factor that in as well.
If it has a grain, then it's likely to be more of a Bog Oak, than it would a jet. I don't believe that it is bog oak, however, it is a possibility.
One would be hard pressed to find any rings made of jet, especially when it includes the shank.
Another possibility is black coral.
Wonderfully imformative discussion. I don't think it is black coral because it would be black completely through.