Agate

Agate is a banded, concentric shell-like chalcedony which can range from translucent to opaque in all hues. When cut into thin slabs the opaque colors can appear more translucent. There are endless amounts of agate colors and patterns. 

Agates are found as round or oval shaped nodules and sizes can range from less than an inch to several yards in length.

Many types of commonly sourced agate come from Brazil and Uruguay, agate has also been found in Germany, the US, India, Mexico, China, Madagascar, Italy, and Egypt.