Polished Porphyry . PO 118 dendritic opal 75 mm x 60 mm

75 mm x 60 mm x 8 mm thick

Fragile mineral specimen not suited to cutting

Very rare fossil stromatolite slab

220 mm x 160 mm x 10 mm thick

Polished Porphyry . PO 118 dendritic opal 75 mm x 60 mmPO118. 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