Thundereggs look like regular rocks from the outside, but contain intricate and colorful mineral patterns inside — often made of quartz, chalcedony ... the size of the crystals that form ...

Naomi Sarna has been working on a grapefruit-size sculpture of a Siamese fighting fish, coaxing it from a piece of blue ...

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 ...