PO123. Pink porphyry slab, cut and polished on one side.
From
Mindoolah, Western Australia.
Dimensions at widest points approximately 140 mm x 80 mm x 8.5 mm thick.
Weighs 188 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.
