Actually, pure salt water freezes differently than salty ice. If you chill salty water slowly, the water freezes out as pure ice, leaving the salt behind. That’s how you get salt-free icebergs floating in the ocean.
Crazy, right? The ocean is salty, but icebergs are basically giant ice cubes that refused the salt. They’re the picky eaters of the sea.
In labs, scientists have made salt water freeze into a strange solid called hydrohalite. It’s a crystalline structure of salt and water. It only forms at -6°F (-21°C) or colder. Antarctica’s briny pools make this stuff naturally. It looks like slushy diamonds.
