Earth's D'' layer is essentially an undercurrent of rocks that particularly aligns the crystals of post-perovskite.

Viewed in the right light — and very close up — slices of stone turn into a riot of color. These jewel-like images are no secret in the world of geologists, but University of Padova professor ...

As Mila Carretero, geologist and coordinator of the Pulpí Geode, explained, a geode is a cavity inside a rock that is covered with crystals. Sitting against a backdrop of oversized crystal spars ...

The sulfur crystals, as seen on May 30, are elemental sulfur, or pure sulfur. Curiosity determined what the crystals were made of. Credit: NASA/JPL-Caltech/MSSS ...

These crystals are produced in molten rock as it travels from deep inside Earth to the surface. ... This is called sector zoning and looks like an hourglass inside the crystal.

NASA announced this week that rocks made of pure sulfur have been discovered on the Red Planet. The yellow sulfur crystals in a pure form have never been seen before on Mars. Earlier findings have ...

NASA announced this week that rocks made of pure sulfur have been discovered on the Red Planet. The yellow sulfur crystals in a pure form have never been seen before on Mars. Earlier findings have ...

Where the crystals were found – the Gediz Vallis channel – may have been carved by flows of water, according to NASA. Curiosity Mars rover captured this view of Gediz Vallis channel on March 31.