Thundereggs look like regular rocks from the outside, but contain intricate and colorful mineral patterns inside — often made ...

Smith Rock State Park is a striking natural area in central Oregon known for its towering volcanic rock formations.

It’s almost certainly as close as I’ll ever get to walking on the moon. Surrounded by giant sandstone-coloured volcanic rock formations, we could be on the set of "Star Wars" or "Planet Of The Apes." ...

(CNN) — Gold and other precious metals are leaking from Earth’s core into the layers above, eventually making their way up to the surface during the formation of volcanic islands like Hawaii, a new ...

The geochemistry of agate and chalcedony in volcanic rocks represents an intricate record of silica precipitation and crystallisation processes occurring under variable thermal and chemical conditions ...

I first caught a glimpse of Fort Rock through an opening in the trees along County Road 5-10, about an hour drive southwest of Bend. The circular outcropping of volcanic rock, known as a tuff ring, ...