Forbes contributors publish independent expert analyses and insights. David Bressan is a geologist who covers curiosities about Earth. Discovered in 1999 during mining operations in the Mina Rica (the ...

An abandoned mine in Spain hides a sparkling treasure – the world's largest geode, a natural crystal phenomenon that has stunned scientists. In abandoned silver mine in Pulpí, in Spain's south-eastern ...

Boulder, Colo., USA: The geode of Pulpí is an 11-meter hollow ovoid with crystal-paneled walls. It is like those familiar couplets of stone interiors covered with bright crystallites, but so large ...

The development of plans for a large geode was clearly the most challenging assignment for McNamara Alumni Center's structural engineers, Minneapolis-based Meyer, Borgman and Johnson (MBJ). The ...