Agate is a variety of chalcedony, a cryptocrystalline form of quartz. It comes in an endless array of patterns and colors, meaning no two agate stones are exactly alike. Agate is often recognized for having a “banded” appearance, most noticed when it is sliced to reveal bands of color similar to rings in a tree. Agate is said to be a “stabilizing” gemstone, emitting a low, calming frequency and used for grounding.