Pink gems can be spent on 2-cups equipment, blue - on 3-cups equipment and yellow - on 4-cups equipment.

They can be spent in different ways:

- purchase the equipment in the Puzzle Store (it only works when you've collected all the Puzzle Pieces);

- spend them in exchange for a new Puzzle Piece

New Puzzle Pieces can only be exchanged for fully assembled equipment: the 2-cup machine can be exchanged for a 3-cup Puzzle Piece, 3-cup machine - same 4-cup Puzzle Piece.
When you exchange the equipment for a Puzzle Piece, you will always get a piece that you don't have yet. You will never receive a duplicate 😊