Ocean Jasper is a trade name for a multicolored stone from Madagascar, typically with spherical patterning. Although commonly described as an orbicular jasper, the most recent research suggests it is the mineral chalcedony instead. Some pieces have agate banding or druses of clear quartz, a coating of tiny crystals, known more commonly as "druzy".
The variety of quartz known as chalcedony is often unfamiliar to people. It is actually the mother stone of many semi-precious gems: banded chalcedony is better known as agate, red as carnelian, and black as onyx, etc. Ocean Jasper's capacity to transmit light is a characteristic of chalcedony. By definition, Jasper is not translucent unless cut extremely thin.