AGATE is a variety of chalcedonic quartz that is distinguished by the presence of color banding in curved or irregular patterns (see illustration). Most agate used for ornamental purposes is composed of two or more tones or intensities of brownish-red, often interlayered with white, but it is also commonly composed of various shades of gray and white.

Agate is translucent and contains inclusions that give it an appearance reminiscent of familiar natural scenes.