GeologyRocks

The fotos are not that sharp but I think it is save to say that that rock is either a flintstone or a piece of weathered volcanic glass. I am favouring the flintstone though especially because it seems to have some chalk on it (the white spots).

BTW, perhaps a bit late but welcome to the forum. I was a bit absent the lask weeks.

... or it's furnace slag.

Rock 2 on your blog looks even more like slag too.

the location it was found might help.

The white stuff is actually brown it is dirt but I have washed the rock and that dirt will not come off.I don't know were it camr from it was given to me by a friend a loooong time ago.Thank you for the welcome and the new information I am going to do a little more research with the new info.

can you recognise and bubbles or air inclusions in the rock maybe with a magnifying glass?

yes there is bubbles

then it is more pointing into the direction of slag i think. flintstone usually does not have recogniseable bubbles, volcanic glass might though. telediagnosis is always a bit tricky.

I don't know if you what you call flintstone is what I call flint rock but if it is the type of rock that you use to make really good and easy sparkd with I already have plenty of that that is like abundent where i am from and also if it is the same thing this rock is nothing like them. I did some looking and only found one picture that looked close to it but the other was black. So any more info would be helpful and thank you again!

flintstone = flint rock for me, yep.

i think slag is most likely for your piece. though flink rock can also be brown, greenish, greyish.

O.K and thank you once again you know it is so funny that we are so far away and still use some of the same terms huh? Well I will do some more research and see what I can find out and if I ever do find out I will post so it will help somone else that is havingthe same problem as me.

perhaps the easiest way to confirm this would be to find a mineralogist or petrologist from a nearby museum or university.

yeah I think that it would be easier that way too! But in another way it takes alot of fun out of it too! LOL !! Well once again thank you!

I think we've all been caught out on furness slag at some time or another.

I also spent a long time in my early days of playing with minerals trying to find out what the brittle black irridescent stuff was that some one kindly brought back from France for me.  - Silcon carbide!!!

Also - Beware of 'fingers' of malachite crystals.  It is often crushed malachite glued round copper tubing.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant