Welcome to the Crystal Maze Sudoku (inspired by the Channel4 TV game show)!
Crystals comprise a cross of 5 cells, all different values.
The four cells orthogonal to the centre cell in Red crystals sum to the two-digit value given in the centre.
The Purple crystal is more valuable than gold, its centre sum of the four cells is a square number.
The four cells of Gold crystals also sum to a square number, but two crystals are fools gold - so do not sum to a square number!
Normal Sudoku, Killer, and Little Killer rules apply.
White dots between cells indicate the two cells differ by one.
Solve the puzzle online at F-Puzzles
Solution code: Enter the digits from row 4 followed by the digits from column 8.