Polished Porphyry slab. PO 128 chatoyance Dimensions at widest points approximately

Dimensions at widest points approximately 130 mm high x 60 mm wide x 35 mm thick

Dendritic Mookaite slab

Dimensions at widest points approximately 190 mm  x 100 mm wide x 50 mm thick

Brecciated Pink Opal rough rock

225 mm high x 155 mm wide x 70 mm

Polished Porphyry slab. PO 128 chatoyance Dimensions at widest points approximatelyPO128. Pink porphyry slab, cut and polished on one side. From Mindoolah, Western Australia. Dimensions at widest points approximately 110 mm x 85 mm x 8. 4 mm thick. Weighs 213 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 dolerite. The