No gemstone is more creatively striped by nature than agate. This distinct and dramatically banded variety of chalcedony is composed of quartz layers. This composition varies greatly and can be of many colors. The other chalcedony family, jasper, has less-regular patterns and is less defined than the agates. Another difference between the two is that agates tend to be translucent (or at least contain translucent bands), while jaspers are generally opaque. This distinction stems from agate being composed of microscopic "fibers" of crystalline quartz while jasper is made of microscopic "grains" of crystalline quartz. Each individual agate forms by filling a cavity in a host rock. As a result, agate is often found as a round nodule with concentric bands like the rings of a tree trunk. Find out about agate's metaphysical properties and more below.