unknown find from slatey

[user 4386]

I doubt if vinegar is strong enough - we use 50% hydrochloric but battery acid would work (but is even more dangerous). For dolomite HCl has to be hot but not for calcite (you can boil magestite in acid and it will never dissolve). Hydrochloric acid is sold for cleaning masonry and called muriatic acid (sulphuric is sold as spirits of salts). Safe way is a bit of hollow glass tubing, dip the end in acid and put your finger over the top end of the tubing to keep the acid in the tube - move over specimen and remove your finger to drip on specimen. We geos get it mixed 50% and carry it in neoprene drop bottles in leather belt cases that we get from companies like Prospectors Supplies (wish they would learn that the metal studs we do the flap up with reacts with acid though). There are lots of other carbonate minerals - smithsonite, cerussite, ankerite, siderite, rhodochrosite, witherite, and strontium carbonate (memory of mineral names is failing a bit) and they react with acid of different stregth and temperature to varying degrees which helps identify them and clean off from other minerals.

Go to Geological Survey of Queensland site and look at their map key for different scale geological maps and download. I think the one I sent you was from the great new "Geology of Queensland" volume. Volcanics to the south are Cenozoic not Cretaceous they are the ones I already sent a mud map of that occur from something or other ridge to Duaringa - but there would be a detailed geological map available with roads and a coordinate grid. I think there might even be one in that book which isn't with me now.

 

[user 4386]

Try, because it is good to get used to that site for maps. If you get stuck ask me again in a few days. They mostly extend south from east of and including Biloela from memory (to west of Duaringa), and Mt Scoria may be part of the area. jeez mate, you are asking a Victorian, I haven't been in your area for a few years now!

 

[user 4386]

The area you are talking about is far east of the Callide Valley - I think the Duaringa 250K sheet although there should be a 100k map in that
area

 

[user 4386]

Might even be NW Monto or west Rockhampton 250K sheet (near the join of the three sheets

 

[user 4386]

You want the area north of the map above, between Biloela and the Fitzroy. Although Cenozoic basalts extend north of the Callide, a quick look does not show basalt extending to nearly as far north as the Fitzroy and the highway other than the Cretaceous basalts on the previous coloured map I posted. There are older basalts though, shown as Permian on this old map (however the same map shows the Mt Hay rocks as Permian and we now know them to be Cretaceous):

 

[user 4386]

You need the modern Mt Morgan 100K geology sheet and it is not free. But I am not sure that the rocks you want are in that area.

 

[Lefty]

Ok, just tried it with vinegar - yes, it appears to fizz gently with vinegar. Will upload photos of the piece sometime in the next few days. There was a smaller bit with the white material on top and bottom like a sandwich, not sure where that one is but the bigger bit has it only on the top.

The middle and left cabs are the Yellowstone agate, the one on the right is from this material, minus the white layer of course.

 

[SimonK]

Hi I was wondering if someone knows what this is as its different to all the other rocks I have seen around slate I have seen.
I'm not much of a rock collector but I think it maybe a piece of petrified wood but not sure.

Hi, is this petrified wood for sale? thanks