Here is my Orb of the Prophets from Star Trek Deep Space 9. The orb is in two versions, one hollow in two parts and one solid. There are two versions of case too, one with brackets and one without just in case someone wants to glue it all together.
The gem stones you have print separately and then slot them in. You might have to resize them a bit depending on how well calibrated your 3D printer is.
The hole in the base is for the future upgrade. Orb inside will have LED's and will be on mini turn table.
I'm a geeky physicist and I'm obsessed with 3D printing and 3D design :D