Banded Iron Formation – 320g, Marble Bar WA (3.45 Billion Years Old)

A piece of Earth's deep history — this banded iron formation (BIF) specimen weighs 320 grams and originates from Marble Bar in the Pilbara region of Western Australia, one of the most geologically significant locations on the planet. At approximately 3.45 billion years old, this specimen dates to the Archaean eon, when Earth was a fundamentally different world and the first primitive life forms were only just beginning to alter the chemistry of the oceans and atmosphere.

Banded iron formations are among the most ancient sedimentary rocks on Earth, formed when dissolved iron in the early oceans was oxidised by the oxygen produced by early photosynthetic microorganisms — most likely cyanobacteria — and precipitated to the seafloor in alternating layers of iron-rich and silica-rich sediment. The result is the characteristic banding of deep red-brown iron oxide (haematite or magnetite) and pale grey-white chert that makes BIF one of the most visually striking of all ancient rocks.

One side of this specimen has been polished to reveal the full depth and clarity of the banding in extraordinary detail, while the reverse retains its natural, unworked surface — offering both the raw geological context and the refined beauty of the stone in a single piece.

• Rock type: Banded Iron Formation (BIF)
• Age: Approximately 3.45 billion years (Archaean)
• Origin: Marble Bar, Pilbara, Western Australia
• Weight: 320g
• Finish: Polished on one side, natural reverse