Sonic's Singularities and Such

Welcome to the secret laboratory where Dr. Eggman's latest experiment has gone haywire! It seems he's created a singularity, but it's not just any singularity. Oh no, it's a Sonic Singularity!

Apparently, it's so dense that it can only hold ONE item at a time. But what could it be? Is it a Golden Ring? A Time-Traveling Toaster? Or maybe even a miniature Chaos Emerald?