A precious stone, as clear as diamond.
Seek it out while the sun's near the horizon.
Though you can walk on water with its power,
try to keep it, and it'll vanish in an hour.
Answer: Ice.
This riddle appears in the following downloadable PDF files:
Can you solve one of the most famous logic puzzle ever?
Memory Matching game for kids, adults and seniors.
Connect the matching tiles and pop them all.