The Ryukyu Islands of Japan, in which Okinawa is part of, has
been formed over hundreds of thousands of years. The island chain has been formed due to plate
tectonic convergence. The Ryukyu Islands
rest upon the Eurasian Plate which are moving southeast and the Philippine Plate
(the oceanic plate) is subducting under the Eurasian Plate (the continental plate),
which is creating a trench and forcing the Eurasian Plate to rise. As the Philippine Plate is in the process of
subduction, molten rock from the oceanic plate is forced upwards, also causing
the islands to rise. This island chain
is clearly not a Hot Spot, like Hawaii as you can see it from the trench off
the eastern shore line. 
The rock types that can be found on Okinawa would most
likely be basalt and coral. These would
be found because the island of Okinawa was once on the ocean floor. Basalt is a Mafic Extrusive Igneous rock.
Coral is a Biological Sedimentary rock, formed by limestone with coral, shells,
fossils, and calcite. The coral on the
island of Okinawa has formed many caves on the island through years of weathering.
