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.


It occurs on our mining claim at Mindoolah near the town of Cue in Western Australia.


   porphyry-close-up.jpg (120795 bytes)    porphyry-tabletop.jpg (45659 bytes)   cut-porphyry-block.jpg (61374 bytes)          porphyry-sphere.jpg (190414 bytes)           porphyry-spheres-etc.jpg (53697 bytes)            porphyry-slab.jpg (72156 bytes)   

 digging-porphyry.jpg (62287 bytes)  porphyry-outcrop.jpg (351501  bytes)

porphyry-outcrop-2.jpg(309817  bytes)

  Click here to view cut & polished specimens of porphyry for sale



We mine a second variety called "Chinese Writing Stone" . It is a porphyritic basalt with groups and rosettes of plagioclase feldspar.


Age of the Mt. Roe baslt that it occurs in is approx. 2,800 million year.


The location is in the Pilbara region of Western Australia near Whim Creek.

 Chinese Writing Stone.jpg (788569 bytes) 


Another variety occurs in farming country near the town of Beverley not far from Perth.   Someone once said that the feldspar crystals in the dolerite looked like cat foot prints. Now the name "cats paw" porphyry has stuck.

cats-paw-tabletop.jpg (16786 bytes)  cats-paw.jpg (64512 bytes)  catspaw-location2.jpg (175502 bytes)  catspaw-location.jpg (169363 bytes)








Send mail to glenn@outbackmining.com with questions or comments about this web site.
Last modified: March 13, 2004