The bewildering shapes apparently owe their origin in large part to how rock can strengthen when squashed from above.
Deep within the Earth's rocky mantle lies oceans' worth of water locked up in a type of mineral called ringwoodite.
The new substance will forever remain in Earth's rock record, researchers say.
NASA's Mars rover has drilled into its third Mars rock, exposing pristine material that will help scientists better understand the past habitability of the red planet.
A blood-engorged mosquito fossil is the first of its kind ever found in a shale rock, as opposed to amber.
Astronomers have detected exoplanets that orbit so close to their host stars that rock would vaporize and possibly condense in the atmosphere to create a very alien 'rock snow' flurry.
Oxygen may have filled Earth's atmosphere hundreds of millions of years earlier than previously thought.