Original 3D Crystal Puzzles are among the most challenging, perplexing and fun puzzles you will build. Each puzzle contains uniquely interlocking, colorful, transparent 3-dimensional puzzle pieces with step-by-step puzzle solutions available online for extra help with more difficult puzzles. This three-dimensional brainteaser jigsaw puzzle is enjoyable to work on, challenging to complete, and beautiful to display. This puzzle is designed for ages 12 and up.