Ocean jasper is one of the many varieties of cryptocrystaline quartz, which includes others such as agates, chalcedony, and various other jaspers.

Ocean Jasper is relatively new to the market, and I don't think I ever found it at shows earlier than 6 or 7 years ago. It is found along the Northwest seashore of Madagascar, and supposedly can only be collected when the tides are out. I guess this is why it is called Ocean Jasper. It has amazing colors that range from pink, green, white, yellow, purple, and red. It has orbicular patterns throughout (eyes) which give it its distinctive look. Relatively expensive when it first came to the market, it has now become more affordable.

Ocean jasper cuts very nicely, although you have to watch for cavities in the stone sometimes lined with small quartz crystals. Sometimes these vugs can add to the uniqueness of the cut stone. I particularly like the white/green example below.