Any ideas, help needed

[The yabby]

Gday all, can anybody identify this rock, it sets off a metal detector, is somewhat magnetic and looks to have a brownish red stain in parts. Was found in the Bathurst area, I did take it to the prospecting shop I hired the detector from, at first the guy said it was probably slag that was scrapped off the surface of a furnace,(I thought if it was scrapped off the top of molten metal and hit the ground it would splatter not form a lump as big as my fist) then another guy from the same shop said no its a volcanic rock and the brownish red marks/stains were rust from iron within the rock, they both said it wasn't worth anything wich is fair enough, but then they asked what I was doing with it and if I didn't want it they would take it off my hands and put it in a display, with that an alarm bell rang in the air space between my ears, worth nothing but they wanted it,hmmm sounded a little strange to me..
For some reason I can't add the photos so if anyone is interested or think they may be able to help let me know and I'll email pics to you, thanks

 

[Ramjet]

Hi Yabby.
You should be able to upload a photo.
It must be under 1 meg.
If you are trying to link a photo from an external location you have to get ten posts on the forum. This is to stop spammers.

Check this thread in forum support.

https://www.prospectingaustralia.com/forum/viewtopic.php?id=585

Cheers

Ramjet

 

[WalnLiz]

Once you get a photo downloaded we may be able to throw in a few ideas on what it could be. Bit hard from a description, but interesting to see the guys wanting to help throw it out for you. :/

Cheers Wal.

 

[Ramjet]

Here is a pic of the rock Yabby is asking about.
I'm posting it for him as he is having problems uploading pics.

 

[loamer]

Looks like a hot rock to me. They will most certainly set of detectors. Worthless if a hot rock. If it is, smash it and watch the 'detectability' drop off significantly.

"A hot rock can loosely be defined as: any rock or stone not containing a valuable mineral (gold, silver, or copper) which generates an audible signal response on a metal detector. The exact cause of this phenomenon has been debated among detectorists for some time. Numerous theories have been proposed, however those that seem most reasonable to me are the ones that focus on the iron-bearing minerals found within most hot rocks. These minerals are predominately the iron oxides: magnetite, hematite, limonite, maghemite and lepidocrocite. All of these oxides exhibit a varying degree of ferromagnetism and can be magnetized by being exposed to another magnetic field; like the one generated by a detector's search coil. If the coil is swept across a high iron content hot rock, a secondary magnetic field will be created around it. This secondary field will then be sensed by the coil's primary field and trigger an audible response via the headphones or speaker."

 

[The yabby]

Thanks for the info loamer, wasn't expecting it to be worth any thing. I just found it weird that a rock was setting off a metal detector and the guys at the shop wanted to take it off my hands.
A special thanks to ramjet for taking the time to putthe pic up for me

 

[richo966]

your right to keep some thing some one is keen to display there must be reason why they wanted it

 

[The yabby]

Not sure why they wanted to "display" it. Maybe the size,as It's a touch bigger than my fist, but other than that not sure.

 

[user 1769]

It might be as simple as just wanting a demonstration hot rock...