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Most oolitic forms are in reference to round forms in a matrix of contrasting material. Ocean jasper is a good example as is Poppy Jasper from here in California.
Oolites and orbicular jasper aren’t even close to being the same
thing.
Oolites usually occur as limestone made up of tiny spherical
carbonate particles, called ooliths, cemented together. Ooliths have
a concentric structure with a diameter up to 2 mm/0.08 in. They were
formed by chemical precipitation and accumulation on ancient sea
floors. The surface texture of oolites is rather like that of fish
roe. The late Jurassic limestones of the British Isles are mostly
oolitic in nature. (Credit Tiscali Reference).
According to the US Geological Survey and other sources, orbicular
jasper forms when a silica rich rhyolitic ash flow cools quickly.
Quartz and feldspar crystallize in spherulites, radial aggregates of
needle like crystals, that provide the interesting structure seen in
this kind of jasper. Better-known examples of orbicular jasper are
often seen offered as Poppy Jasper or Morgan Hill Jasper from
California or Ocean Jasper from Madagascar.
Rick Martin