Polished Porphyry . PO 118 dendritic opal Very rare fossil stromatolite slab

Very rare fossil stromatolite slab

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

Weighs 166 grams

Fragile mineral specimen not suited to cutting

Weighs 516 grams

Polished Porphyry . PO 118 dendritic opal Very rare fossil stromatolite slabPO118. 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