PO129. Pink porphyry rock, cut and polished on one side with a rough, natural back and a cut base to sit as a display specimen.
From Mindoolah, Western Australia.
Dimensions at widest points approximately 110 mm x 90 mm x 45 mm thick.
Weighs 620 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 clinozoisite has replaced but retained the shape of plagioclase feldspar crystals.
