Stromatolitic Dolomite SD159 prehnite Difficult to photograph but is

Difficult to photograph but is a pleasing lilac colour

PU120  Purple Chalcedony rough rock

RH227  A slab

All reasonably uniform in size (roughly 20 - 25 mm diameter)

Stromatolitic Dolomite SD159 prehnite Difficult to photograph but isSD159 Stromatolitic Dolomite slab, polished on one side. Sections consist of a chaotic mixture of dolomite and or stromatolite fragments set in a matrix of mudstone and or coarsely crystalline dolomite . The pink and red colouration can be attributed to the presence of finely disseminated iron oxides . It often contain layers and nodules of red chert. From the Irregully Formation, Western Australia. Dimensions approximately 165mm x 105mm x 8mm thick