Chalcedonies include many types of cryptocrystalline quartz gems and feature a number of different colors. Geologists can tell a chalcedony from the arrangement and structure of its crystals.

and quartz. Both can be different colors, like black, brown, red, blue or green, depending on what other elements are present. However, manufacturers use these resources in different ways when ...

“Let’s say you have Quartzite A in your kitchen, and I have Quartzite A in my kitchen—both of them will still be different. In quartz, it will be the same: If I go for Color A and you go for ...