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Author Topic: What is this rock?  (Read 2580 times)

Offline Atomic-S

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What is this rock?
« on: 14/02/2012 01:14:04 »
Recently someone brought into the shop of geological arts where I work, a rock measuring about 10 cm in diameter, generally round and rough-surfaced as if sanded for a long time in a riverbed, but having a few small (about 5 mm) dents of about 2 or 3 mm depth, as well as a larger shallow irregularity in one place that could possibly be called a dent. The oddest thing about it was its unusual weight, suggesting a composition largely of some heavy element. I did not think it was a meteorite due to its general lack of dings over most of its surface, but its great weight is mysterious. Any ideas?


 

Offline Bass

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Re: What is this rock?
« Reply #1 on: 14/02/2012 05:42:11 »
Can you give us more to go on than the fact that it's round, dented and heavy?
 

Offline Sprool

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Re: What is this rock?
« Reply #2 on: 15/02/2012 13:08:46 »
Really not much info to go on, but high density would assume some high level of metals in there. Common metals might be most likely iron oxides, maybe manganse or copper oxides (but often that would give characteristic colour) so I would assume it's some sort of iron-rich stone. Whether it is igneous, sedimentay or metamorphic in origin is impossible to say with the sparse information given. How about a photo?
 

Offline Mazurka

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Re: What is this rock?
« Reply #3 on: 16/02/2012 10:08:35 »
A photo would be good.

If it looks like one mineral  (rather than lots)  What can scratch it / it can scratch (http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness)

And what is the colour of its streak (http://en.wikipedia.org/wiki/Streak_(mineralogy))
 

Offline Atomic-S

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Re: What is this rock?
« Reply #4 on: 18/02/2012 02:10:57 »
Can you give us more to go on than the fact that it's round, dented and heavy?
Unfortunately, no. The guy left with it, and I don't know who he is, nor did I get any photos nor other test data.
 

Offline Atomic-S

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Re: What is this rock?
« Reply #5 on: 18/02/2012 02:12:21 »
I was however wondering if the information given could be consistent with any known terrestrial rock. Do volcanic rocks ever have an iron-like density?
 

Offline Bass

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Re: What is this rock?
« Reply #6 on: 18/02/2012 05:06:02 »
The short answer is yes- there are iron and other metal deposits that are associated with volcanic rocks.  What color was the rock?  Black?  Reddish brown? Yellowish brown?  Could you see any metallic minerals? Could you make out any crystals or cleavage? Do you think you could scratch it with a knife?  Any oxidation?
There are several non-metallic minerals with high density- for example barite (white) or wolfremite (black), so any additional information you could provide would help.
 

Online Bill S

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Re: What is this rock?
« Reply #7 on: 03/03/2012 23:44:09 »
Sounds like a fubarite! :)
 

Offline JimBob

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Re: What is this rock?
« Reply #8 on: 07/03/2012 01:35:55 »
Sounds like a fubarite! :)

Now, now lets be kind. Really sounds more like an itcouldbeite.
 

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Re: What is this rock?
« Reply #8 on: 07/03/2012 01:35:55 »

 

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