Thanks to DrewTM and BodyParts3d for sharing the original files. "BodyParts3D, © The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan"

This is a box version of the anatomically correct (on the exterior) human heart that can be used as a STEM project box, a jewelry case, a geeky valentine's day box, etc. I added 4 sphere cuts to represent chambers (obviously these inside cuts are not anatomically correct).

Basic Set: (best for chocolates or other small <36mm items)

• The base part "Heart_Base06.stl" will need supports. I used a max overhang of 65 degrees and it worked out fine.
• The top part "Heart_Top04.stl" can be safely printed without supports and has 4 basic 36mm hemisphere cuts to match the bottom.

Stem Set: I made a STEM project friendly set that allows:
-- wires to be run down the stem to the base.
-- wider cut on top hemisphere for project space.
-- small wire grooves and guides on the sides

• The Base "STEM_Heart_Base07.stl" will need supports. I used a max overhang of 65 degrees and it worked out fine.
• The Top "STEM_Heart_Top07.stl" can be printed as oriented. Supports are suggested but optional on this part. The supports, if turned on, may prevent the inside hemisphere cuts from sagging or getting a little stringy.

The circles will just fit the Rocher candies if you remove the little brown cup paper on the bottom and just keep on the gold foil. If you need to fit bigger items or bigger chocolates, then scale up. Each Sphere cut is 36mm in diameter (about 1.4") by default.