- #1
Can you identify these minerals?
- Thread starter z.js
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Discussion Overview
The discussion revolves around identifying a mineral and rock specimen found at a rocky beach, with participants sharing their observations, hypotheses, and questions regarding its composition and characteristics. The scope includes mineral identification, geological properties, and experimental methods for testing the sample.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
- Experimental/applied
Main Points Raised
- One participant suggests the mineral might be quartz, while another proposes it could be agate embedded in an igneous matrix.
- Several participants express uncertainty about the identification based solely on a photograph, questioning the effectiveness of the UV light test used by the original poster (OP).
- Questions are raised about the physical properties of the sample, including hardness, density, and magnetic response, with some participants suggesting specific tests to determine these characteristics.
- Another participant describes the specimen as potentially resembling tar filled with gravel, while others speculate on its geological context.
- There is a discussion about the potential for the black material to be a mineral or a metal, with references to the Mohs scale of hardness for proper identification.
- Some participants mention the possibility of conducting flame tests or heating the sample to observe its behavior, although there is caution against heating it without proper knowledge.
- One participant humorously reflects on the beauty of minerals found in kidney stones, while another expresses curiosity about the appearance of quartz crystals in the sample.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the identification of the mineral and rock. Multiple competing views and hypotheses are presented, with ongoing questions and uncertainties regarding the sample's characteristics.
Contextual Notes
Limitations include the reliance on a blurry photograph for identification, the lack of detailed physical testing results, and the need for more specific information about the sample's geological context.
- #2
Simon Bridge
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I doubt we can tell exactly from the picture.
What do you mean by "UV light ... didn't work"?
How did you employ the UV light?
What were you expecting?
What happened?
It looks like quartz or agate embedded in something igneous... but really just some white stuff in some grey stuff.
Have you shown it to a geologist? A local rockhound?
What do you mean by "UV light ... didn't work"?
How did you employ the UV light?
What were you expecting?
What happened?
It looks like quartz or agate embedded in something igneous... but really just some white stuff in some grey stuff.
Have you shown it to a geologist? A local rockhound?
- #3
daqddyo1
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I need more information.
At first glance, this slightly blurry photo suggests your rock is a piece of tar filled with fine gravel.
How hard is this sample? (Can you scratch it with a knife?, with your finger nail?, etc.)
How dense is it? Does it feel like it might be metal?
Does it respond to a magnet?
At first glance, this slightly blurry photo suggests your rock is a piece of tar filled with fine gravel.
How hard is this sample? (Can you scratch it with a knife?, with your finger nail?, etc.)
How dense is it? Does it feel like it might be metal?
Does it respond to a magnet?
- #4
Philippe Bzh
- 4
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black rock
Hi, I think at first sight the black rock can to be magmatic rock, very hard (isn't?). Quartz, right! And perahps a metal meet. At see later and good chance!
z.js said:Can you help me identify this mineral and rock? I can't.
I think the mineral is quartz.
I tried the UV light, but it didn't work.
(Mebbe it's something precious!)
Hi, I think at first sight the black rock can to be magmatic rock, very hard (isn't?). Quartz, right! And perahps a metal meet. At see later and good chance!
- #5
Evo
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It looks like tar and gravel to me.
- #6
256bits
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Simon Bridge said:
I expect the OP was checking for fluorescence and phosphorescence of certain minerals.
http://www.galleries.com/Fluorescent_Minerals
The picture looks like some nest cleaning aggomeration from some burrowing animal of years gone past. Difficult to tell from the fuzzy picture.
- #7
Simon Bridge
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Probably - still, nice not to have to guess and I like to encourage more scientific reporting in scientific sites ;)
That hadn't occurred to me...
I think the bottom line is that there is not enough data.
Short answer: "no".
- #8
PhysicoRaj
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I have a lot of information about rocks 
(whether they're minerals or not) because I have played with them 
and even swallowed a lot of them when I was small.
At what place did you find it? A hillock? Roadside? Riverside?
(whether they're minerals or not) because I have played with them and even swallowed a lot of them when I was small.At what place did you find it? A hillock? Roadside? Riverside?
- #9
z.js
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It was found at a rocky beach which was also a fossil site. (Flat Rocks, Inverloch, Australia)
- #10
PhysicoRaj
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Did you check for the three things prescribed by daqddyo1?
- #11
PhysicoRaj
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After that heat a 'piece' of the 'bottom' part of the stone (bottom in the picture, a thick black layer) on your stove without allowing the flames to lick it. Does it melt?
- #12
z.js
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The black stuff at the bottom scratched metal. It has a density of about 2.8 g/cm3, and it is not attracted by a magnet. I will see if it melts when I heat it. How hot is a normal alcohol burner?
- #13
PhysicoRaj
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Hot enough to know if it makes a good rock or not!z.js said:
Anyway let's see if it melts.- #14
256bits
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z.js said:
There are many metals - lead, tin, copper, iron, steel.
You need the hardness of the rock based on a scale to properly identify.
http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness
- #15
seany
- 9
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please make a sharper shot? It can also be some other sedimentary matirx than tar and gravel
- #16
z.js
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256bits said:
The black stuff scratched a steel knife.
- #17
PhysicoRaj
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z.js said:
Then don't go to heat it.
- #18
Enigman
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Go raid a chem lab:
http://en.wikipedia.org/wiki/Qualitative_inorganic_analysis
(I miss flame tests
)
http://en.wikipedia.org/wiki/Qualitative_inorganic_analysis
(I miss flame tests
)- #19
z.js
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PhysicoRaj said:
I did...
The black stuff that the mineral was stuck in seems to be tar. The black rock at the bottom didn't.- #20
z.js
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Enigman said:Go raid a chem lab:
http://en.wikipedia.org/wiki/Qualitative_inorganic_analysis
(I miss flame tests
You know I can't do that!
I miss flame tests too!
- #21
PhysicoRaj
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z.js said:
You mean it didn't melt? If it were really a mineral, but I don't think it is a mineral very precious. You can do the flame test in your alcohol burner. But that would not give interesting results.
You have a wide (very much) range to match with what you have got. But I don't go for metals.
- #22
z.js
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I was asking about the little things that looked like quartz, not the black stuff.
- #23
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The minerals of a kidney stone can be quite beautiful!
- #24
PhysicoRaj
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One must be proud to have them inside!
- #25
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