What is this stone?

[NC field hunter]

A customer brought this stone into my place of work today. He thought I would be able to tell him what it is. I personally think it's that grey stone used on the railroad. He thinks it's chert and I can see why he would. It just isn't dense enough to be chert. Any ideas? TNmts, I remember you mentioning working on the railroad. What is the grey pitted stone called?















Thanks for any help!!

 

[The Grim Reaper]

Looks like slag to me which is the by product of blast furnaces. My area had lots of blast furnaces back in the late 1800's and we have that type of slag everywhere around here.

 

[monsterrack]

It does look like slag, I would take a chip off to see the inside.

 

[GatorBoy]

Railroad track ballast is loaded with that same exact material: along with broken up granite down here.
Its slag see all the air bubbles in it

 

[rock]

Yep slag. I find all different colors of it here

 

[Tnmountains]

Gator nailed it on saying ballast stone.Rail Road. But that may be a natural porous stone. Here is a point from a rock shelter that has a lot of little holes in it like a sponge it weighs nothing. Made for a neat find. Hopefully this picture will show it.

 

[Twitch]

Rusty - pretty sure it's slag. Did that big lime spill affect you all? I know it screwed your river up a bit.

 

[NC field hunter]

I do agree it is more than likely from a furnace. I retubed an old boiler once that was caked with a similar substance. As I recall, what came from the boiler was less dense. Boy, I'll never forget that job. The boiler was made in TN. it's name brand was "look out"! Kinda unnerving for a kid doing a job over his head to look up and see "look out" staring at him. Any way, I have always recognized slag as a glass. Is any byproduct of this type called "slag"?

 

[Tnmountains]

It was Eureka foundry below Lookout Mtn in Chattanooga I bet. You able to see a lll the holes in that rock shelter point?

 

[NC field hunter]

Rusty - pretty sure it's slag. Did that big lime spill affect you all? I know it screwed your river up a bit.

It didn't affect our water but it sure does look bad. You know I love that river. I say it didn't affect us but who really knows. Our city water is linked to the Dan river in a twisted interstate of water. I think we'll be fine unless the river starts flowing in reverse. In that case, their is no need for me to worry, we are all screwed! Lol! Thanks for asking bro.

 

[NC field hunter]

It was Eureka foundry below Lookout Mtn in Chattanooga I bet. You able to see a lll the holes in that rock shelter point?

Rich, that is a spongy looking point. Strange! Before I left work, I walked out and looked at the boiler. You are correct! Had our city officials known what we were doing and the blast we could have caused with that old boiler, we'd probably still be locked up. Lol! Thanks for helping guys!