Stone doesn't turn into a solid, I suggest you put iron(molten), sand and broken quartz(molten) in the middle, remove stone and broken metal and have less gravitons. Using radial gravity could be useful, but you try and see what works, right now the planet isn't really a planet, looks more like stone particles flying around in a cloud.
You should use something hot ~1200C that cools and turns into a solid later. Stone just doesn't look right... because planets form of hot materials that later cool down and harden when the planet "stabilises".
If you downvote, tell me why.