Reticulite is a volcanic rock from the big island
of Hawaii! This lava is produced by fire fountains that are
charged with gasses ...creating foam that is ripped off and
thrown up by wind and blown 10's of miles away.This can
create "Reticulite Dunes." Looks very much like "sponge"
but it is lava.
Its apparent specific gravity is 0.025g/cm3.
Reticulite is a term used by volcanologists.
This piece was collected in the 1930's, from an eruption near
the Kilauea Craters, Hawaii.
This beautiful specimen comes in 1.25-inch hinged perky, with info.