There are lots of types of rock and each type has different properties and uses. For example, some are strong and hard but others are soft and sandy. Some rocks are harder than others. For example ...

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 ...

New research reveals how rock strength plays a crucial role in erosion, shaping landscapes over millions of years.