Is there a surtling core 3d print?

Hello 3D printing vikings!

Im in need for the cube design of surtling core and i can think of magma blocks and or stone cube, but it wouldnt be identical. Due to the in game model looking uneven, and it has a almost ball inside of the cube(?) im trying to find same design.

Any idea where to find the surtling core print? What website?