This large piece has been ground gem smooth and a professional polish applied to reveal the algae's tree like structure in amazing detail and colours. It is a type of bio-thermal calcareous mudstone that has an algal stromatolitic component. The dendrites/tree structures are the remains of blue/green algae that grew on the floor of a warm sunlit shallow, tropical sea some 215 million years ago. A wonderful and large specimen.
A beautiful example of this uncommon brachiopod shell which is complete and has been preserved in solid calcite. It was discovered in 1971 and has remained in the same collection ever since. A really nice addition for the collector.
A really good specimen with excellent detail throughout. The main specimen is attached to another sponge (Tremacysta sp). This fossil sponge would make an important addition for the collector of UK fossil sponges.
