Opal Pineapple segment

This is an incredibly rare Segment of an Opal 'Pineapple' 

This unique opalised mineral is found only in White Cliffs NSW, Australia.

It is a double pseudomorph (opal after calcite after ikaite ) 

it changed crystal structures twice & was later replaced by Opal. 

An incredible set of circumstances had to occur in the Earths history for this to happen. 

A great piece for a new collector.