Heart necklace that takes advantage of gyroid infill. This stunning piece of jewellery is a perfect gift for someone special. 
Print instructions. Read carefully!

To properly print this model, you first have to add a modifier to the object so that it just covers loop for a necklace, as shown in picture. Then as global settings under strength make wall loops 0, top shell layers 0, bottom shell layers 0, infill pattern to gyroid, apply gap fill to Nowhere, and maximum length of the infill anchor to 0. Then you can play around with infill density and fill multiline (at least two recommended) to test different patterns. I would recommend infill density between 10-25% and multiline between 2 and 4. Then under objects, choose the modifier block and change wall loops to 4. You can also easily add tect to the bottom of the model to personalize the necklace. 

A simple silver or gold necklace will make it a beautiful gift.