Jump to content
phrunt

Help Identifying Mystery Rock / Metal

Recommended Posts

I was out detecting with my Equinox and had a solid 21-22 on the VDI numbers, it never flicked off those numbers, it was down about 15 cm's.  I dug it up expecting a NZ $1 or $2 coin, both come up the same numbers.

I was puzzled when what I ended up finding was a rock looking object

This is it next to an older NZ 10c coin I found only minutes before hand

10cent.thumb.jpg.32a934eec6377d3593b30eac31a970e0.jpg

To me it looks more like a rock than a bit of metal, I tried to hit it as hard as I could with a hammer to see if it was a chunk of lead or something thinking that would flatten it, it didn't make a mark on it. I then hit it with the back flat end of my Log splitter thinking this will surely do some damage to it, but no, it didn't leave a mark, all it did is cracked the concrete under the mystery object.  This thing is extremely tough.

It weighs 17 grams and feels quite heavy for it's size and not magnetic.

What could it possibly be? 

rock2.jpg.731ee994d8587d35e335a36068391f58.jpg

 

  • Like 1

Share this post


Link to post
Share on other sites

Maybe a specific gravity test might reveal what it is

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites
20 hours ago, normmcq said:

Maybe a specific gravity test might reveal what it is

That's a good start.  If it's 10 or higher you really narrow down the possibilities.  There are zillions of metals in the 7-9 range and Murphy's Law says it will be in that range.

 

Also, 'cutting' a small groove with a triangular file might show the untarnished color of the natural metal.  It's easy to identify copper (possibly not pure but alloyed) that way.

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

Look up the mohs hardness scale and run some of those tests to determine its hardness, then look up streak testing and perform that (for streak testing you will need a white un glazed piece of ceramic, or black depending on the color of the streak).  

With its hardness and streak known as well as some of its other attributes you should be able to narrow it down.  

 

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

That is a weird one Simon. I can't see how any natural "rock" would not have shattered under the abuse you gave it. (How hard did you hit it?:biggrin:)  But the concrete under it did.:ohmy:  Bugger. Hope wifey did not growl at you.:laugh:. It obviously has metal in it or it is all some kind of metal. I doubt very much it is of a natural occurrence especially from your locality. Man made perhaps. Tungsten?? Seems pretty tough, unless you just really gave it a girls hit/tap. :laugh:

JW :smile: 

  • Like 2

Share this post


Link to post
Share on other sites
3 hours ago, kiwijw said:

It obviously has metal in it or it is all some kind of metal. I doubt very much it is of a natural occurrence especially from your locality. Man made perhaps. Tungsten?? Seems pretty tough....

I thought of tungsten, too.  Density test will sort that in/out since tungsten specific gravity is close to gold.  It's the only affordable metal that is up there (specific gravity, that is) with the valuable gold and platinum group metals.  I've wondered if it would be a good practice metal for gold panning, sluicing, etc. but I've never read it being used for that.  Hard?  About as hard a metal as you can find.

But what is a chunk of tungsten like that doing there??

  • Like 1

Share this post


Link to post
Share on other sites
6 hours ago, GB_Amateur said:

I thought of tungsten, too.  Density test will sort that in/out since tungsten specific gravity is close to gold.  It's the only affordable metal that is up there (specific gravity, that is) with the valuable gold and platinum group metals.  I've wondered if it would be a good practice metal for gold panning, sluicing, etc. but I've never read it being used for that.  Hard?  About as hard a metal as you can find.

But what is a chunk of tungsten like that doing there??

I have no idea, it's an unusual shape too, it looks natural.  

I'm going to do all the tests on it, hopefully tomorrow if I can get the time, lifes been busy the past week, Jim Hemmingway sent me a good field guide that will help with that also. I'm just interested to see what it is, I know its not of any value but its the mystery that has me.

We had visitors today and the guy was baffled by it and was surprised how heavy it is for the size of it, he thought it looked natural too.

I was showing him how hard it is and I had a stainless steel nail and got him to hit the nail into it, the nail had no hope.

On the smooth spots it reflects light.

I did get growled at as it was our path 🙂, I seem to get in trouble a lot lately... this new hobby of mine is a trouble maker 😄  I hit it with a log splitter, even a girl can do damage with that thing!!!

The gold chance indicator on the Gold Monster 1000 slams right over to positive.  I know it's not gold but that means its a strong non-ferrous I guess.

I think it's tungsten as a guess, I found this article which indicates tungsten maybe found in my area

https://www.stuff.co.nz/southland-times/news/104465700/potential-for-rare-earth-minerals-in-southland

 

 

  • Like 2

Share this post


Link to post
Share on other sites

I managed to clean up my metal rock a bit using an angle grinder, it becomes a nice silver colour after doing that, also, I did a very basic specific gravity test on it and it came out at 19.12

20180821_124624.jpg.b997a8532e8380423ed998e59fa6261b.jpg

The grinder didn't change the shape of it but it cleaned the outer layer of dark stuff off

 

  • Like 2

Share this post


Link to post
Share on other sites

A specific gravity of 19 would suggest tungsten but naturally occurring pure tungsten is often brittle. Single crystal tungsten would be hard but rare. Tungsten carbide would have the hardness but a lower specific gravity. An x-ray fluorescence test will give you the answer.

Here is a map of tungsten locations in NZ:

 

40F38330-08FF-461F-849C-D4AE1F92B425.png

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By phrunt
      Buyers Beware!
      There are fake X-Terra's now hitting the market from China, no doubt they'll be flooding the market soon.  This particular one for sale has left the Minelab logo off the control box, but you can bet they have them with the original logo for sale too.  I hope the Equinox is not next now that they're standing to clone the lower end Minelab models rather than just the PI's.  I would now be careful buying any X-terra new or second hand that's not from a Minelab dealer or trusted seller. I hope Minelab can tell if existing detectors are genuine in an easy way like they do for their GPX/GPZ detectors.  Serial numbers are often not enough as if they work out the algorithm Minelab have used to create their serial numbers they can create fake numbers that match real numbers out in the marketplace or they just use known serial numbers on them...
      https://goo.gl/oieVt4

      😞
      The same store has a another detector for sale, looks a lot like a Fisher to me which I haven't noticed as a clone before.

       
       
    • By phrunt
      My pursuit for an old classic metal detector is still in full swing, I've found one I think I want, it looks like something they took up on the space shuttle to the moon 🙂

      It's in full working condition and looks to be very tidy
      At the moment it's on auction at 95 NZD (65 USD) with no buyers interested at all.
      I am trying to find the manual to it to make sure it's the detector I want for my collection.  Does anyone have the manual or know where I can find it, google isn't being of much help.  I haven't been able to find too much on it at all except some guys on other forums who have discovered one for sale and snapped it up to try get it running.  Fortunately this one is working.
      Thanks for any help, any information on it would be outstanding.
       
    • By Tnsharpshooter
      I didn’t realize this.
      Example
      https://www.whiteselectronics.com/cart/
    • By phrunt
      Has anyone used the DP (Delta pitch) setting on their T2 or F75 or other Fisher/Teknetics detector that has the mode?
      I've been experimenting with it as my standard choice was always 2+ tones but I figured DP would give me more information but perhaps it doesn't as it overloads my brain a bit.
      Would there be a depth loss using this mode?  Are any particular tones mode deeper than others? 
      At first I felt a bit of a brain overload in DP but after time it started to grow on me and it seemed alright, I was able to use the tones to identify coins without having to look at the screen as I was able to recall the tone noise of the coins but then it's not like I'd be able to know the tone of every decent find and 2+ feels more comfortable on the ears 🙂 , I assume DP mode has 99 tones.
      I tried 3b which is meant to reject bottle caps but it sure doesn't reject NZ bottle caps, no difference at all on them so I guess it's optimized for American bottle caps like Budweiser or something 🙂
      The T2 seems a bit of a weapon with the stock 5" coil, very good at separating trash from good finds in a trash ridden area so I'm spending a bit more time on it lately.
    • By Steve Herschbach
      I love turning people on to detecting. It is the real reason these forums exist. The truth is I don’t know much about anything, but there are a couple subjects I know pretty well. Metal detecting is one of them. In my over 35 years as a major multi line dealer (retired) I have personally answered almost every question that can be imagined about metal detecting. I did not know the answers all the time, but I am the sort that if I don’t know I will tell you that, go find the answer, and get back to you. I find it very valuable to my own learning because on the next go I will have that answer already. It is those decades of people asking questions that stuffed all that detecting information into my head. In particular, I have a huge amount of experience with detectors of all brands and types and I could care less about who makes what politics. I only care about what works.
      I enjoy people new to this oddball thing we call metal detecting because I am so passionate about metal detecting myself. I just think it’s the greatest hobby in the world - no offense meant to you more serious types. Metal detecting has provided me with countless adventures and memories and I would wish anyone to have had as much fun as I have had over the years.
      Are you new to the forum? I see lots of new people signing up. Are you new to detecting and here to learn? Don’t be afraid to ask questions! This is not the forum where you will get told that the question has been asked before so go find the info or whatever. Forums exist for people to ask questions, but I see behavior on other forums that I do think intimidates people and makes new people afraid to ask a simple question for fear of being made to look dumb.
      If it helps I am dumb as a post on most stuff. There is no shame in that. I don’t know everything so how to learn but ask the questions?
      Anyway, I just wanted to put that out there because I really am here to help new people as best I can. There are a lot of extremely knowledgeable people here and frankly they don’t need my help. My hope is they are also here to help people. Lots of them are better prospectors and detectorists than I am. I don’t claim to be the know all of detecting and I sure don’t claim to be the best at any of it. But I do know this. I really enjoy helping people. It lights me up and makes my day. If you have a simple question of any sort, please ask. Why not make Steve’s day by asking that question? The only thing I ask is be patient getting the answer. I do have busy times where I need a little time to get back but I will in almost any situation reply same day or at most the next.
      😀😀Steve Herschbach

×