My personal sign. Made of polished and etched obsidian inlaid with gold paint. Three years later it fell onto the floor and broke.
Later I find out it is based on a scene in Sonic SatAM episode "Ghost Busted" (Season 2 episode 6b)
I used the show version in some online roleplay; another player sent me a sketch with no reference and suggested I wear it.
25 years later I finally watch the episode.