Homeowners and experts alike regard quartz as one of the best materials for kitchen countertops. It's strong, durable, ...

Pink ChalcedonyA pink chalcedony shows off its beauty. Chalcedonies include many types of cryptocrystalline quartz gems and feature a number of different colors. Geologists can tell a chalcedony ...

Amethyst is a purple variety of quartz believed to help calm the mind, heighten intuitiveness, increase focus, and enhance memory – making it a great lucky charm to wear before an exam.

I share the reluctance of modern petrologists to propose new variety names for rocks. There are, however, cases in which a variety name is justifiable to imply a significant physical, chemical or ...