Polished Porphyry . PO 118 dendritic opal From near Norseman

From near Norseman

Very rare fossil stromatolite slab

Dimensions at widest points approximately 140 mm x 95 mm x 9 mm thick

Weighs 516 grams

Approximate dimensions at widest points 235 mm  x 140 mm  x 13 mm thick

Polished Porphyry . PO 118 dendritic opal From near NorsemanPO118. Pink porphyry slab, cut and polished on one side. From our mining claim at Mindoolah, Western Australia. Dimensions at widest points approximately 180 mm x 95 mm x 12 mm thick. Weighs 384 grams. Porphyry is a general term that is used rather loosely for igneous rocks which contain relatively large isolated crystals set in a fine grained groundmass. The porphyry pictured here has pinkish coloured clinozoisite crystals set in a ground mass of