Agatized fossil coral is highly prized by both fossil collectors and mineral collectors for its beauty and scientific value.  You can see the rarity and exceptionally unique beauty of this top-grade specimen, which includes half of an agatized geode from a large fossil coral colony.  The internal chamber is lined with stalactitic formations of chalcedony in an attractive bright white, coating a tan base color.  Oligocene-Miocene era (23 MYO) fossil corals were simple marine invertebrates that possessed a sac-like body called a polyp with a mouth and tentacles.