As with the crown chakra candle mould this model should be printed in ABS plastic. My preference is the ease at witch the model can be sealed and smoothed with acetone once printed giving you a superior finish. The model can be assembled with the walls facing inwards and the edges sealed temporarily with some form of tape. As a silicone rubber mould. If you prefer you can Print 2 x bases and the 4 walls, then assemble them with pattern outwards so that you can cast the module as a silicone mould. If you are going to do it this way then I suggest using acetone to glue the parts and seal the joints permanently before you submerse in silicone rubber.
Print settings: Extruder @ 245 deg c Bed @ 60 deg c Layer height @ 0.2mm Infill @ 15% Print speed @30mm/sec
Extra:The heart chakra, or anahata chakra in Sanskrit, is located at the center of the spine at heart level. Anahata roughly translates to, “unhurt.” Accordingly, the heart chakra acts as the individual's center of compassion, empathy, love, and forgiveness