How do you complete a 3D jigsaw crystal puzzle diamond?

To complete a 3D jigsaw crystal puzzle in the shape of a diamond, start by sorting the pieces by shape and color for easier assembly. Begin with the base or largest sections, connecting pieces together by fitting them snugly without forcing them. Gradually work your way up, ensuring each piece aligns correctly based on the guides provided by the puzzle's design. Finally, secure the last pieces in place, and display your completed diamond puzzle for a stunning visual effect.