Jasper is a form of opaque cryptocrystalline silicon dioxide (SiO₂ or silica). Jasper is usually characterized by bright colors, including green, red, blue, and many others.
Jasper is distinct from agate due to its opacity. A true jasper blocks all light, although some brecciated jaspers will have pockets of chalcedony in them.
Jaspers, like agates, have a loose classification system based on how their surface patterns emerge. Some varieties also have their own names and specific colors.A few common varieties include: