Indonesian Shells 		

Java island, Indonesia

Neogene 

Shell. Coralliophilidae.   

It is very rare coral burrowing snail Magilis antiquatus Montfort, 1810 from the Gastropod Family Coralliophilidae.
The snail is embedded in probably Favia sp. from the Coral Family Favidae. Neogene, Java island, Indonesia.
It is replaced by chalcedony in uncalcified coral chunk. Weight of this item is 420g. They get such from the bottom of the Pasific ocean.