Piranha Agate Brazil 28,67 ct

Brazilian agate cabochon with unusual black inclusions.

These inclusions are rare bacterial microcolonies that formed between the bands of the agate during its formation. These extremophile bacteria metabolised manganese and the conical shape of the structures indicates that they were growing upwards to balance the concurrent growth of the chalcedony substrate.

It comes from the state of Paraná in Brazil, where this agate is known as Piranha Agate.