Hard archive
Every past Hard puzzle, and only this one: each mode has its own sequence, so Hard #4 and Daily #4 are different minerals. Today's is not listed, because it would give the answer away.
Play puzzle 0
Play puzzle 1
Play puzzle 2
Play puzzle 3
Play puzzle 4
Play puzzle 5
Play puzzle 6
Play puzzle 7
Play puzzle 8
Play puzzle 9
Play puzzle 10
Play puzzle 11
Play puzzle 12
Play puzzle 13
Play puzzle 14
Play puzzle 15- Play puzzle 16
Play puzzle 17
Play puzzle 18
Play puzzle 19
Play puzzle 20
Play puzzle 21
Images are public domain or openly licensed. Each one is credited on the Credits page.