Crystallized Water

Source
Dropped by various water elemental themed creatures in Northrend zones, such as:
 * Ice Elemental and Iceshard Elemental in Howling Fjord
 * Corrupted Rager and Crystalline Ice Elemental in Dragonblight
 * Frozen Elemental and Boiling Spirit in Borean Tundra
 * Aqueous Spirit in Sholazar Basin
 * Frozen Earth and Crazed Water Spirit in Zul'Drak

Found while mining Cobalt and Rich Cobalt Deposits, as well as from Titanium Veins.

Found occasionally while fishing.

Harvested by Engineers using the Zapthrottle Mote Extractor on Steam Clouds in Sholazar Basin and Borean Tundra, as well as occasionally from Arctic Clouds in other zones.

Crystallized Water as an ingredient

 * (1 Eternal Water = 10 Crystallized Water and vice versa)

Alchemy

 * Mighty Fire Protection Potion

Blacksmithing

 * Brilliant Saronite Breastplate
 * Brilliant Saronite Helm
 * Brilliant Saronite Legplates
 * Cudgel of Saronite Justice

Enchanting

 * Enchant Boots - Icewalker

Engineering

 * Froststeel Tube
 * Mana Injector Kit
 * Volatile Blasting Trigger

Leatherworking

 * Black Chitinguard Boots
 * Cloak of Tormented Skies
 * Dark Frostscale Breastplate
 * Dark Frostscale Leggings
 * Dark Nerubian Chestpiece
 * Dark Nerubian Leggings

Tailoring

 * Duskweave Boots