Archaeologists spotted fragments of quartz called 'rock crystal' at the site. The fragments were spread all around but were heavily concentrated in the burial mounds. In all, 337 pieces were ...

Pure quartz, or “rock crystal” from Brazil. Source: Didier Descouens, CC BY-SA 4.0 Pick up a rock almost anywhere on Earth and chances are pretty good that there’s at least some quartz in it.

More than one of our readers suggested we highlight this beautifully-shot process documentary about the laborious and precise manufacturing of piezoelectric quartz crystals in the early 1940s.

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 ...

Geodes, for instance, are created when mineral-rich water seeps into hollow spaces within rock formations and slowly evaporates, leaving behind dazzling crystals like quartz and amethyst.