Orbicular Jasper

Hardness: 6.5-7 on Mohs scale. Color: Typically green, white, cream, or brown with distinct circular or 'orbicular' patterns. Luster: Dull to vitreous. Crystal Structure: Trigonal (microcrystalline quartz). Generally opaque.

Orbicular Jasper is a form of chalcedony with spherical inclusions. It typically forms from volcanic flows or hydrothermally altered rocks. The characteristic 'orbs' are believed to be the result of a complex process involving silica-rich fluids precipitating around a central nucleus, or by spherulitic growth of quartz and feldspar. Geological age can vary widely depending on the specific deposit, often associated with volcanic activity from the Mesozoic to Cenozoic eras.

Primarily used as an ornamental stone and in jewelry (beads, cabochons, carvings). It is also collected by mineral enthusiasts due to its distinctive patterns.

Orbicular Jasper is known for its beautiful and unique patterns, which feature 'eyes' or 'orbs' within the stone. One of the most famous varieties is Ocean Jasper, found only in Madagascar, which often displays a wider range of colors and more intricate orb patterns. The patterns are not always perfectly round; they can be elongated or irregular.

Orbicular Jasper is identified by its unique spherical or 'orbicular' patterns, often in contrasting colors to the base material. Field identification involves observing these characteristic patterns and testing for hardness (it will scratch glass). It's commonly found in volcanic regions, with notable deposits in Madagascar (Ocean Jasper), Mexico, and the United States (e.g., California, Oregon) among others. Collectors should look for vibrant colors and well-defined orb patterns when selecting specimens.