Chalcedonyis a cryptocrystalline form of silica, which has a waxy luster waxy luster, and may be semitransparent or translucent. Chalcedony assumes a wide variety of colors, but the most common are white to gray, grayish-blue or a shade of brown ranging from pale to nearly black. Each colour is it's own variety.
Agateis variety of chalcedony with multi-colored angular or curved banding. Aventurineis is a form of chalcedony, translucent and containing platy mineral inclusions that give a shimmering effect termed aventurescence. Carnelianis a clear-to-translucent reddish-brown variety of chalcedony; the hue may vary from a pale orange, to a deep nearly-black coloration. Onyxhas black and white banding Sardonyxis a variant of onyx with brown, red, orange and white banding