Natural Brown Jasper Smooth Pear Drops Briolette Matching Pair Beads Sold per 8 beads & Sizes from 12.5mm to 14mm approx. Onyx is a banded variety of chalcedony. It comes in many colors from white to almost all other Jasper, a form of chalcedony, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue.