Jasper is an opaque, impure variety of silica, found usually in red, yellow or brown colors. The name means "spotted stone" - derived from the French word 'jaspe'.
The most common form of Jasper is red, but the Greeks referred to a green form of Jasper which is very rare and a highly prized stone today. Jasper can appear with mineral impurities, patterned from the formation process and flow patterns of the volcanic sediment that was saturated with silica to form bands or swirls in the jasper rock. It can also be found with dendritic minerals alluring to the appearance of tiny plant growth. Picture jasper exhibit several of these variations at once, resulting in what appear to be picturesque scenes in a slab cut specimen.