When I hear Gothic, I think Chrome Hearts...and to a lesser extent, Scott Kay, King Baby, Stephen Webster. Some of David Yurman's newer pieces fit that description as well.
DH's ring, it was custom made, it is s.silver with y.gold detail and I think the stone is Lapis Lazuli. Just to get inspired, if you want you can take the pic to your jeweler and have something similar made.
I like the Cartier Santos-Dumont ring; it's quite modern (as well as classic) and substantial. The white gold/falcon's eye combo also makes it look a somewhat Gothic. I have this ring in yellow gold and tiger's eye and I love it.