Heart stopper rock
- Thread starter Goldfreak
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Ship of fools
Mat. T
It looks good, I have some pyrite in my collection just because it looks good.
Matt T
Matt T
20xwater said:
And he's not wrong! I don't know if it's always the case, but it certainly can be the case.
Kalgoorlie's famous Golden Mile was overlooked in the initial rush to follow up Paddy Hannan's discovery of alluvial nuggets derived from visible gold in quartz veins at Mt Charlotte, because the fabulous riches of the Golden Mile - a couple of kilometres away - mostly comprised almost-invisible particles of gold inside crystalline iron pyrites. Talcum powder inside sugar crystals is a convenient way to visualise it. More than 60 million ounces later and they're still digging!
Matt80
Matthew
Yep plenty of major mines were discovered by finding pyrites. Sometimes the gold is free mill alongside or mixed with the pyrites and sometimes the pyrites have no gold but pointed the way to gold close by.
Often gold in pyrites needs to be roasted and processed to release the gold, but this can be quite dangerous unless you know what your doing so get help or do a lot of research and if you do decide to try it ensure you have plenty of airflow. Pyrites can contain a lot of nasties, they look pretty, but often the fumes can be lethal if heated. It's really not rocket science roasting them, but certainly not something to do without being very aware of the risks. If you can find a bunch of the stuff it might be worth sending in a sample to be assayed.
Bloody nice looking rock even if it is the wrong type of yellow.
Often gold in pyrites needs to be roasted and processed to release the gold, but this can be quite dangerous unless you know what your doing so get help or do a lot of research and if you do decide to try it ensure you have plenty of airflow. Pyrites can contain a lot of nasties, they look pretty, but often the fumes can be lethal if heated. It's really not rocket science roasting them, but certainly not something to do without being very aware of the risks. If you can find a bunch of the stuff it might be worth sending in a sample to be assayed.
Bloody nice looking rock even if it is the wrong type of yellow.
Sorry, I don't understand why you are calling it sand, whatever it is occurs on rock in your photo. Are you saying that if you put the rock under the tap it would all wash off, or that you could brush it all of with your hand - that it is simply resting on the rock and has come from somewhere else and dumped onto the rock? To this ageing geo with failing eyesight it looks like a rock that has broken along a planar surface which was originally an extremely thin veinlet of iron sulphides, probably marcasite. So that the thin coating of marcasite is left adhering to the rock surface. The later photo shows that it is entirely crystals, which I doubt would have washed from somewhere else and retained that shape. Marcasite commonly has that flat crystal form, unlike pyrite which usually shows cubes when it is crystalline - therefore I suggested pyrite rather than marcasite.
I think I understand why you said magnetite now - the rock itself on your earlier photo looks like slate not magnetite to me, but your latest photo (unfortunately still a bit too blurry) does appear to have both white mineral (calcite or quartz?) and a black mineral (magnetite?) intergrown with the sulphide mineral (marcasite?). I would separately test the sulphide-magnetite vein (if that is what it is) and the rock well away from the vein, with a magnet.
Pyrrhotite is another common iron sulphide mineral that is magnetic like magnetite but looks like pyrite. But my money is on a lump of slate that has broken along a very thin marcasite (or less likely pyrrhotite)-magnetite-calcite (or slightly less likely quartz) veinlet, parallel to the plane of the veinlet. Such planar veinlets form planes of weakness that the rocks tend to break along. I see such veinlets daily in slate areas of central Victoria and central-west NSW.
Based on identification from a blurry photo which if in focus would test a mineralogist without further mineral properties.....
I think I understand why you said magnetite now - the rock itself on your earlier photo looks like slate not magnetite to me, but your latest photo (unfortunately still a bit too blurry) does appear to have both white mineral (calcite or quartz?) and a black mineral (magnetite?) intergrown with the sulphide mineral (marcasite?). I would separately test the sulphide-magnetite vein (if that is what it is) and the rock well away from the vein, with a magnet.
Pyrrhotite is another common iron sulphide mineral that is magnetic like magnetite but looks like pyrite. But my money is on a lump of slate that has broken along a very thin marcasite (or less likely pyrrhotite)-magnetite-calcite (or slightly less likely quartz) veinlet, parallel to the plane of the veinlet. Such planar veinlets form planes of weakness that the rocks tend to break along. I see such veinlets daily in slate areas of central Victoria and central-west NSW.
Based on identification from a blurry photo which if in focus would test a mineralogist without further mineral properties.....
Your a champion brother...Nice visual work?goldierocks said:Sorry, I don't understand why you are calling it sand, whatever it is occurs on rock in your photo. Are you saying that if you put the rock under the tap it would all wash off, or that you could brush it all of with your hand - that it is simply resting on the rock and has come from somewhere else and dumped onto the rock? To this ageing geo with failing eyesight it looks like a rock that has broken along a planar surface which was originally an extremely thin veinlet of iron sulphides, probably marcasite. So that the thin coating of marcasite is left adhering to the rock surface. The later photo shows that it is entirely crystals, which I doubt would have washed from somewhere else and retained that shape. Marcasite commonly has that flat crystal form, unlike pyrite which usually shows cubes when it is crystalline - therefore I suggested pyrite rather than marcasite.
I think I understand why you said magnetite now - the rock itself on your earlier photo looks like slate not magnetite to me, but your latest photo (unfortunately still a bit too blurry) does appear to have both white mineral (calcite or quartz?) and a black mineral (magnetite?) intergrown with the sulphide mineral (marcasite?). I would separately test the sulphide-magnetite vein (if that is what it is) and the rock well away from the vein, with a magnet.
Pyrrhotite is another common iron sulphide mineral that is magnetic like magnetite but looks like pyrite. But my money is on a lump of slate that has broken along a very thin marcasite (or less likely pyrrhotite)-magnetite-calcite (or slightly less likely quartz) veinlet, parallel to the plane of the veinlet. Such planar veinlets form planes of weakness that the rocks tend to break along. I see such veinlets daily in slate areas of central Victoria and central-west NSW.
Based on identification from a blurry photo which if in focus would test a mineralogist without further mineral properties.....
