This ring from Jeulia is perfect for the Nightmare Before Christmas or goth fan in your life (they have a skulls section…) because the items in that section do have that vibe.

They are a bit light on details, other than saying the ring is sterling silver and “plated”. There is a stone they describe as a “Jeulia stone” but do not specify what that might be. Worth asking for specifics if you are interested, as it sells for USD$118.