Baryte on calcite.

Baryte on calcite.

Baryte, BaSO4 Barium, sulphate. Specimens such as this one are very distinctive, and easily recognisable as coming from the Isle of Sheppey. The Isle is largely formed from the London clay. Within the clay are found septarian nodules coated with yellowy brown calcite resembling marzipan, upon which are perched radiating crystals of baryte. Even though there has been much research, the process of how they are formed is still a mystery.