Found some random crystals!!

[Shingles]

Hi guys,
Found this rock while gold detecting recently, not really a gem guy so have no idea what they are. Any thoughts?
FYI this wasn't the only one, there were heaps of rocks like this.

 

[silver]

Looks cool Shingles.

 

[AtomRat]

Mabey a chlorite or calcite on schist / gneiss. Follow the breadcrumbs and check for other colors, as it may lead to an interesting point. South Aus?

 

[Shingles]

Mabey a chlorite or calcite on schist / gneiss. Follow the breadcrumbs and check for other colors, as it may lead to an interesting point. South Aus?

No mate. Central Queensland.

 

[Rockhound]

Looks a bit like peridot.Nice find.

 

[Lefty]

Looks a bit like peridot.Nice find.

That's what I reckon. Nice find Shingles - with our remarkable Central QLD geology, you never know what could turn up.

Cheers

 

[casper]

Looks a bit like peridot.Nice find.

yup! aka olivine

 

[Heatho]

Olivine Basalt.

 

[Marauder]

yeap totally Olivine, brought home about 20 kgs of it from Mortlake last week!

Strange to find it in QLD though

 

[TTKooAu]

I would be very happy with a find like that, great colours. Nice work Shingles

 

[Marauder]

I read somewhere that you have to wax olivine crystals or they will become dull after awhile, i think the same is for peridot, due to oxidisation(which is odd cos they are a silicate(already oxidised?))

They guy from mortlake said if your gonna display them put some clear varnish on it, otherwise they will go funny.

James

 

[Lefty]

yeap totally Olivine, brought home about 20 kgs of it from Mortlake last week!

Strange to find it in QLD though

Gem-quality peridot is found at Chudleigh Park in Northwest QLD, though I hear the site has been closed.

Given the geology here - particularly down the east coast and sub-coastal regions - I wouldn't find it strange if just about anything turned up. It's an over 2000km long stretch of igneous formations, both intrusive and extrusive. Everything is granite and other magmatic rocks that solidified before bursting through the surface with extinct volcano cores dotted about the place everywhere.

It just boils down to huge swathes of potential gem-bearing countryside that has never been thoroughly prospected, if at all. The last time there was much of that activity going on here, it was well over a century ago and those people were looking for one thing only - gold. They had no interest in coloured pebbles.

Heaps of potential here Though I doubt most of it will ever be realized

 

[Lefty]

I read somewhere that you have to wax olivine crystals or they will become dull after awhile, i think the same is for peridot, due to oxidisation(which is odd cos they are a silicate(already oxidised?))

They guy from mortlake said if your gonna display them put some clear varnish on it, otherwise they will go funny.

James

Yeah, that does sound a bit weird. My father has had some faceted peridot in his collection for about 20 years and they still look as good as the day he got them.

Could there be some other mineral in the crystal cluster that does that?

 

[Shingles]

Thanks for the responses guys! I'm excited to hear that it's peridot. If I had of known that I would have grabbed more.
Next time I'm out that way I'll grab a bucket of nice looking specimens and make them available to members if they're happy to pay for postage.

 

[Lefty]

Have a good look Shingles, there could well be some faceting-grade crystals among them.

Good luck!

 

[Marauder]

Might have been cos peridot and olivine are so soft that they scratch easily.