Polished Marble Bar Chert slab MB114 Opalite Tumble polished Prase

Tumble polished Prase

An unusual feature of some pieces are septarian structures with black colouration

Dimensions at widest points approximately 200 mm x 100 mm x 16 mm thick

Dimensions at widest points approximately 310 mm x 220 mm  x 9 mm thick

Polished Marble Bar Chert slab MB114 Opalite Tumble polished PraseMB114 Marble Bar Chert slab polished on one side . Dimensions at widest points approximately 140 mm x 90 mm x 9 mm thick. Weighs 188 grams. Marble Bar chert is a finely banded, iron rich silica rock from the Marble Bar Chert Member (Warrawoona Group) of Western Australia. Formed in shallow Archean seas, it dates to the Paleoarchean (~3. 46 billion years old), making it one of the Earths oldest well preserved sedimentary rocks. From near the town of