A fictional variety of it becomes the cause for the end of humanity in Kurt Vonnegut's Cat's Cradle.
All natural occurrences of this substance are hexagonal. At lower temperatures and at pressures above 2 kilobar many other phases with different crystalline structures exist; in fact, no other known solid exhibits such a variety of forms. It constitutes 80% of Pluto as well as 40% of the moons Ganymede and Callisto. A fictional variety of it becomes the cause for the end of humanity in Kurt Vonnegut's Cat's Cradle. FTP, name this ubiquitous substance, cubes of which are found in most people's freezers.
All natural occurrences of this substance are hexagonal. At lower temperatures and at pressures above 2 kilobar many other phases with different crystalline structures exist; in fact, no other known solid exhibits such a variety of forms.
{ice} (accept equivalents)