Orbicular Jasper:

 "It's hard to believe that the large deposit of beautifully patterned jasper on the east coast of Madagascar first written about in 1922 could have been lost for the better part of a century, but it was. Dominated by pinks and greens and circular patterns or orbs, from which the term orbicular derives, this jasper made a comeback in 2000 and was the buzz of the [Tucson] show among those interested in cabochon, bead, or carving materials. Edged with small quarts crystals, some large polished pieces made particularly attractive displays.

    "Orbicular jasper's distinctive patterns are made up of round or spherical inclusions of contrasting colors floating in solid jasper. The orbs can range in diameter  from a millimeter to a centimeter, and frequently show a particularly dramatic concentric banding. How orbicular jasper forms is still a scientific mystery, although a graduate geology student at the  university of California at Berkley is now putting advanced technology to work on this problem."