Lots to see in this RR bed #2 egg!
The boxcore shape of the cavity has been added up by a fissure upwards. The fissure did divide the spherule in two (hard to see in the pic), so could have formed in a later phase in the forming of the lithophyse. At the bottom is the cast of a Calcite crystal visible. Unknown minerals formed the stalactites hanging from the cavities ceiling. The orbs on the fissures wall seem to have formed around tiny yellowish pits. In the orbs and stalactites is a green mineral captured. Pinkish agate and a white chalcedony crust is covering the delicate minerals. At the end clear and white opal has filled part of the cavity.
Another remarkable thing is the renewed growth of the shell in the vicinity of the outer starpoints.
Hell of an egg!