Kentucky agate is a crystalline form of quartz, a silicate mineral, that shows varied colors arranged in layers with some being opaque and others translucent. These "Kentucky Agates" are derived from the Borden Formation of Early Mississippian age and can be collected along some river drainages where the Borden is exposed to weathering. The agates display banding, fortification, eyes, and even some plumes and moss. Color banding is related to chemicals present during formation and show yellow, red, orange, burgundy, lavender and pink.
With such variety the Kentucky agate make splendid display pieces and because agate take a high polish it is well suited for use by jewelry designers and artists.