❓Your Mineral Identification Questions answered here

[user 4386]

Looks like a vuggy volcanic. Recommend getting a sample of the greenish/yellow crystal and determine its specific gravity & follow goldilocks guidelines. My guess - Mix of colours suggest lead mineralisation.

Could be a lot of minerals - even common near-surface iron minerals like goethite ("limonite") and lepidocrocite and jarosite can look very yellow

 

[Daniel77]

Hi Goldierocks, sorry for the late reply.

Sorry mate, I don't know what the properties are, are there tests that I can perform to find out?

I was out today having a look in the same area and found another piece with what seems like the same thing protruding from it, this time the piece is not magnetic like the last one.

Not sure what to make of it, will be going back out on Sunday to have another look.

 

[user 4386]

Hi Goldierocks, sorry for the late reply.

Sorry mate, I don't know what the properties are, are there tests that I can perform to find out?

I was out today having a look in the same area and found another piece with what seems like the same thing protruding from it, this time the piece is not magnetic like the last one.

Not sure what to make of it, will be going back out on Sunday to have another look.

https://www.prospectingaustralia.com/forum/img/member-images/22295/1644569414_20220211_194302.jpg

Go to the Query symbol (Magnifying glass) and type in:

Series on identifying minerals

and also type my name as the person (Goldierocks)

You will find an entire course on mineral identification

 

[Daniel77]

Hi Goldierocks, sorry for the late reply.

Sorry mate, I don't know what the properties are, are there tests that I can perform to find out?

I was out today having a look in the same area and found another piece with what seems like the same thing protruding from it, this time the piece is not magnetic like the last one.

Not sure what to make of it, will be going back out on Sunday to have another look.

https://www.prospectingaustralia.com/forum/img/member-images/22295/1644569414_20220211_194302.jpg

Go to the Query symbol (Magnifying glass) and type in:

Series on identifying minerals

and also type my name as the person (Goldierocks)

You will find an entire course on mineral identification

Thanks mate, looking at it now. :Y:

 

[Phil8303]

Hi guys. Wondering if anyone can name this rock, mineral or even petrified wood? It has some kind of grain on it, is black under white light and shines blue under the UV torch. Actual dimensions, 1cm, by 5mm by 4mm, and weighs 2.54grams. Any clues or feedback would be appreciated. Cheers everyone.

 

[Hawkear]

An interesting specimen.
It is hard to tell whether the specimen is oblong or prismatic from the photos and given the weight and dimension its specific gravity would be somewhere between 6.3 and 12.7 which would put it into the realm of the minerals/rocks which contain a significant content of the heavier elements like lead, tungsten or even uranium and definitely rule out something like petrified wood.
Can you give some idea of the locality in which it was found and maybe some idea as to its hardness ie does it scratch steel knife or glass?

 

[Phil8303]

An interesting specimen.
It is hard to tell whether the specimen is oblong or prismatic from the photos and given the weight and dimension its specific gravity would be somewhere between 6.3 and 12.7 which would put it into the realm of the minerals/rocks which contain a significant content of the heavier elements like lead, tungsten or even uranium and definitely rule out something like petrified wood.
Can you give some idea of the locality in which it was found and maybe some idea as to its hardness ie does it scratch steel knife or glass?

Thanks Geoff. It won't scratch steel, but the streak on a tile left a blue chalk like powder. Believe it or not, I lost my glass for testing so won't upset the Mrs by trying on the house panes. It was found in rocky spot (jasper and BIF area) out at Paynes Find, WA.

 

[Hawkear]

At a bit of a loss but a blue streak is suggestive of a copper mineral but the SG tends to suggest otherwise. Are there any known copper deposits in the Paynes Find area? Also any chance of doing a SG test to nail down that SG a bit more.

 

[Phil8303]

At a bit of a loss but a blue streak is suggestive of a copper mineral but the SG tends to suggest otherwise. Are there any known copper deposits in the Paynes Find area? Also any chance of doing a SG test to nail down that SG a bit more.

I will give the SG test a crack tomorrow and let you know the result. Not sure on the copper deposits. I didn't see a lot of blue or green rock around there, but will do some more research. Thanks Geoff.

 

[Phil8303]

At a bit of a loss but a blue streak is suggestive of a copper mineral but the SG tends to suggest otherwise. Are there any known copper deposits in the Paynes Find area? Also any chance of doing a SG test to nail down that SG a bit more.

Hi Geoff. Assuming I did the formula correctly (divide dry weight of mineral by the weight of it hanging in water), the SG came out at 2.75

 

[Phil8303]

Hi Geoff. Assuming I did the formula correctly (divide dry weight of mineral by the weight of it hanging in water), the SG came out at 2.75 - 2.81

 

[Hawkear]

Hi Phil just checking back with you on that formula. The SG of something is basically it weight divided by its volume ( metric ie grams divided by cc).
Archimedes principle is that when something is submerged in water it experiences an upward force equal to the weight of the volume of water it displaces so therefore an objects volume is numerically equal to the loss of weight it experiences in water. In other words Volume equals Dry Weight less Wet Weight
So SG = DW/(DW - WW)
Assuming that’s what you did 2.75 - 2.81 puts it in a different range of mineral possibilities. Will have to do a bit of researching but being no mineralologist would love others to input some ideas too.

 

[user 4386]

Hi Geoff. Assuming I did the formula correctly (divide dry weight of mineral by the weight of it hanging in water), the SG came out at 2.75

That is very low density

 

[Phil8303]

Hi Phil just checking back with you on that formula. The SG of something is basically it weight divided by its volume ( metric ie grams divided by cc).
Archimedes principle is that when something is submerged in water it experiences an upward force equal to the weight of the volume of water it displaces so therefore an objects volume is numerically equal to the loss of weight it experiences in water. In other words Volume equals Dry Weight less Wet Weight
So SG = DW/(DW - WW)
Assuming that’s what you did 2.75 - 2.81 puts it in a different range of mineral possibilities. Will have to do a bit of researching but being no mineralologist would love others to input some ideas too.

Yep, I've crunched the numbers twice and ot still comes out in the same range. A curiosity.

 

[Hawkear]

That is very low density

Yes that is a very light mineral. Have been pouring through my Pellants Rocks and Minerals but really at a dead end.
is there an online app that we can just plug in what we know already to narrow the ID?
So far we have have
Hardness Less than 5.5 - maybe needs a bottom line there.
SG. 2.75 - 2.81
Colour. Black
Streak Blue (Light blue or dark blue?)
Fluorescence. Weak blue
Given it lightness could be a carbonate based mineral so it’s reaction to a drop of dilute hydrochloric acid might also give a clue.
Of course most States offer mineral identification services but it would be a good learning experience to be able to make a best guess before getting to that stage.

 

[Phil8303]

In a different note, anyone come across these before? SG is close to 2.63 and it feels heavy (96.96 grams) but is non-magnetic. Picked it up near Kununurra recently.

 

[Phil8303]

Yes that is a very light mineral. Have been pouring through my Pellants Rocks and Minerals but really at a dead end.
is there an online app that we can just plug in what we know already to narrow the ID?
So far we have have
Hardness Less than 5.5 - maybe needs a bottom line there.
SG. 2.75 - 2.81
Colour. Black
Streak Blue (Light blue or dark blue?)
Fluorescence. Weak blue
Given it lightness could be a carbonate based mineral so it’s reaction to a drop of dilute hydrochloric acid might also give a clue.
Of course most States offer mineral identification services but it would be a good learning experience to be able to make a best guess before getting to that stage.

I'll keep researching. I'm not against the dilute acid test, although it is small so I dont want to wreck it.

 

[Hawkear]

In a different note, anyone come across these before? SG is close to 2.63 and it feels heavy (96.96 grams) but is non-magnetic. Picked it up near Kununurra recently.

Oh Dear. Possibly a well waterworn plutonic rock like a Gabbro or a metamorphised granitic Gneiss (again from my Pellant).
Unfortunately SG can be less useful for rocks as opposed to minerals as rocks contain a mixture of different minerals and the SG can vary depending on the mixture ratios.
You would need to try to identify the minerals present and that would be a starting point.
Also as likely being igneous in origin, a geological map of the area where the rock was found may name some intrusive rock features nearby.
Edit. Given its waterworn appearance and lightness it may have travelled some distance from its source so look where the nearest watercourse to where you found it crosses or is near an igneous intrusion upstream.

 

[Phil8303]

T

Oh Dear. Possibly a well waterworn plutonic rock like a Gabbro or a metamorphised granitic Gneiss (again from my Pellant).
Unfortunately SG can be less useful for rocks as opposed to minerals as rocks contain a mixture of different minerals and the SG can vary depending on the mixture ratios.
You would need to try to identify the minerals present and that would be a starting point.
Also as likely being igneous in origin, a geological map of the area where the rock was found may name some intrusive rock features nearby.
Edit. Given its waterworn appearance and lightness it may have travelled some distance from its source so look where the nearest watercourse to where you found it crosses or is near an igneous intrusion upstream.

Thanks Geoff. I did find it at the high watermark of creek, so will look upstream.

 

[user 4386]

In a different note, anyone come across these before? SG is close to 2.63 and it feels heavy (96.96 grams) but is non-magnetic. Picked it up near Kununurra recently.

iron pisolites