Here is a Sonic blue lanyard, that comes with a round medallion. The medallion is likely acrylic clear coating over a metal back. It's still mint on the card here, which shows Sonic jumping while facing a mobile phone screen at the viewer. The phone says "Sonic Cafe".What's that? It's…
This keychain isn't officially Sonic, but it was a part of a Sonic promotion when the Sega Dreamcast came out. You can sort of see the reddish/orange-ish swirl on it.