Large crystals found in geodes and other rocks are relatively rare. Pink ChalcedonyA pink chalcedony shows off its beauty. Chalcedonies include many types of cryptocrystalline quartz gems and ...

Evidence for the use of rock crystal - a rare type of perfectly transparent quartz which forms in large hexagonal gems - has occasionally been found at prehistoric sites in the British Isles, but ...

Opinions expressed by Forbes Contributors are their own. David Bressan is a geologist who covers curiosities about Earth. “We were thrilled!” said Dr. David Grant, a researcher at the ...

Piezoelectricity—a crystal can generate ... could explain why large gold nuggets are so often associated with quartz veins found in tectonically active areas or even rocks shattered by earthquakes.

“Here, unexpected little crystals of calcite appear throughout the rock plugging up all the tiny openings. These crystals clog everything up and keep most of the fluid in large cracks with no access ...

Granite is an intrusive igneous rock. Granite has large crystals which can be easily seen with the naked eye. This makes it attractive and useful for kitchen work surfaces. The Devil’s Tower in ...