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* Left: These Water crystals on the three blades are called hoarfrost. Water crystals are formed at very low tempetarures when water vapour in the air becomes solid. Similar things happen  in the freezer  at home.
* Middle: These nice crystal cubes of salt are growing when sea water or ordinary salt water dry up.
* Right: When suger water dries up,  sugar crystals (= candies) are formed.