The gem is roughly the size of a chicken egg.
"I don't think I've seen anything like it," said one seismologist.
The rocks are a missing link from a billion-year old supercontinent.
The research could help scientists understand natural disasters like landslides.
The "world-class" cave complex has a volume of 236 million cubic feet.
But they found that the core was softer than previously thought.
The park is one of the only places in the world where the public can search for real diamonds in their original volcanic source.
Seismologists may have to completely change their models for the area based on latest findings.
Geologists have proposed a new theory for how the British Isles were formed millions of years ago.
Mount St. Helens forms part of the Cascade Arc, a line of volcanoes that extends from British Columbia, Canada, to northern California
The eruption may have wiped out the ozone layer.
A 3D map of the planet shows the ancient configurations of the oceans and continents, and how they have changed over time.
The latest results could help to improve earthquake forecasting in the short term.
A supervolcano is a large volcano that has had an eruption of magnitude 8 or more
Scientists found that Mars's crust formed much earlier than previously thought.
When the Pine Island Glacier melts, it could trigger even more ice to melt and raise global sea levels.
In 1906, a powerful 7.9 magnitude earthquake caused the deaths of up to 3,000 people and destroyed more than 80 percent of the city of San Francisco.
Geologists have identified a new type of fault movement at San Andreas.
The formation was likely formed as a result of a series of explosive volcanic eruptions more than 3 billion years ago.
The finest quality of this green gem is called "peridot."
Plumes of acid rain, vog and lava continue to plague Hawaii's Big Island.
Scientists believe the moon is now moving about 1.5 inches away from our planet every year.
Yellowstone's last major eruption took place around 640,000 years ago, producing a blast that ejected more than 2,000 times the amount of ash spewed out by Mount St. Helens in 1980.
These rocks formed at the bottom of ancient lake beds between three and four billion years ago, when the Martian surface was abundant in water and its climate was warmer.