Anyone know where this breccia came from?

[Shifter55]

I've been collecting rocks ever since I was old enough to walk, and this year I joined my local lapidary club to actually do something with the rough material I'd built up over the years.
Most of it was purple sandstone, quartz, and river rocks but one oddity was a black and gray breccia landscaping pebble. The black fragments were basalt as I had polished a piece of it with similar colour, and the binder some sort of dolomite or calcite mineral.
However the only locations I have found listed for this kind of breccia have been in North America around the western states where volcanic blowouts seem to have fragmented enough basalt to give rise to this stone.
https://www.dropbox.com/s/y6k1ipk63a8r3ex/IMG_20150414_162150.jpg?dl=0
https://www.dropbox.com/s/m2n8lk3npg7asaz/IMG_20150428_152817.jpg?dl=0
The piece I have here is about 17mm long and has fragments with minimal crystal grains in the fashion of the road gravel that they use almost everywhere in Australia. Unfortunately no landscaping suppliers seem to sell breccia and it's obviously very different from the usual chert and jasper breccias commonly used for stonework.
Anyone want to have a crack at trying to figure out where this may have come from? It's possible that it may be of west Victorian origin as similar vuclanism happened there quite long ago.

[Ghost]

Have you shown it to the local stone masons, the guys that make headstones.
They handle a lot of different ornamental stone, and may recognise it and be able to give a source location.
Welcome to ALF.
Regards,
Ghost.

[brett h]

I have some of this but I don't where we can by it.  A great deal of our material has come from South Western Queensland.  I've never cabbed it.

[Fullerton]

It looks similar to larvikite (usually from Norway and USA) that is notable for its feldspar crystals. However, there's not much light in your pics, so I can't see if it has the same sparkle.


Its used for benchtops and lapidary.


Do a google search and see how it compares.

[Shifter55]

Have you shown it to the local stone masons, the guys that make headstones.
They handle a lot of different ornamental stone, and may recognise it and be able to give a source location.

Unfortunately almost all of the stonemasons in my area specialise in the sandstone that the Central Coast is known for, I have contacted a stonemason outside my area in Hornsby but they have not replied yet.

I have some of this but I don't where we can by it.  A great deal of our material has come from South Western Queensland.  I've never cabbed it.

If it has a similar pattern to the stone on the left in the pictures below, it's possible that it may have come from a diatreme area in NSW, even though it is not terribly shiny the fragments polish rather well, don't grind or polish it too roughly though, the cement mineral is quite soft.

It looks similar to larvikite (usually from Norway and USA) that is notable for its feldspar crystals. However, there's not much light in your pics, so I can't see if it has the same sparkle.

I actually have a piece of Larvikite that came with my starter kit, as you can see in the picture below the mystery breccia completely lacks the labradorescence and intergrowth boundaries characteristic of feldspar granites (the sparkles in black regions the last picture are reflections from my car's mica paint).
https://www.dropbox.com/s/r6p9d5lseddqygc/IMG_20150605_120302.jpg
https://www.dropbox.com/s/jdcn8dkrg9fyi9s/IMG_20150605_112002.jpg