# Unusual rock



## Vanish (22 Jun 2013)

I have found this rather unusual rock. Does anyone know what it might be. It's very hard and quite brittle. It almost appears to be melted in areas. 




Here it is again




Here are a couple of others that I'm considering using.


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## MirandaB (22 Jun 2013)

I can't say for certain but it looks like ironstone,not sure if it would be a good idea in an aquarium but someone else might have a better idea on that.


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## Vanish (22 Jun 2013)

I was wondering if it may have iron in it because of the slight brownie colour. Also considered basalt. 
One for the geologists


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## Vanish (22 Jun 2013)

Yup there's iron in it. I chipped a tiny amount off and attracted it to a magnet. Bit of a shame as I like the look of it. Anyway I think the other two will be fine. I may set about the larger one with a chisel, as its a real big lump.


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## MirandaB (22 Jun 2013)

I was afraid it might be  
I don't know about the other 2 rocks,always worth doing the old fizz test with vinegar to see if they're inert or not.


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## gmartins (24 Jun 2013)

it looks like basalt to me. even the melting bit seems to point to a igneous rock such as basalt.


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## dw1305 (24 Jun 2013)

Hi all,


gmartins said:


> even the melting bit seems to point to a igneous rock such as basalt.


I think it is "slag" from metal ore processing. Depending where you are in the UK you should be able to find which metals were mined and refined locally. If it is from steel production it will be quite limy ("basic slag") and contain some phosphorus.

cheers Darrel


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## Unkillable Cat (27 Aug 2013)

Its definitely iron stone. I grew up in Eston playing in the hills that were formerly iron mines and saw a LOT of this stuff.


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## ceg4048 (27 Aug 2013)

Vanish said:


> Yup there's iron in it. I chipped a tiny amount off and attracted it to a magnet. Bit of a shame as I like the look of it. Anyway I think the other two will be fine. I may set about the larger one with a chisel, as its a real big lump.


I don't see why you need to be ashamed. Aren't people running around in a hysteria because they think they need more Iron in the plants diet? There is no reason whatsoever to ban Iron containing rocks from your tank. Iron is a commodity.

Cheers,


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