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. Banded agate is distinguished from onyx by the fact that its banding is curved or irregular, in contrast to the straight, parallel layers of onyx.  

Drusy Facts, Information and Description Drusy, druse, druzy, drusies - Different spellings, but they all mean tiny quartz crystals that form within or on the surface of other stones. When ground water carrying dissolved silica is forced into a porous area of the rock, rapid cooling often occurs, causing the formation of tiny crystals on the surfaces or in cavities of the rock. The clear crystals often form on top of previously deposited minerals. This is called a drusy. A crust of tiny crystals lining a rock cavity, usually composed of the same minerals that occur in the rock.