Need help identify this piece of rock

[Marccc1991]

A coupe of years ago I found this piece of rock in The Ardennes in Belgium/France. By now I became curious what kind of rock this might be. I hope I've finally reached the right place with people of knowledge about this. Any help will be appreciated.

Stone - Album on Imgur

 

[Marccc1991]

I think I already know what the piece I found it.

Glass slag perhaps?

Brislington Community Archaeology Project - Virtual Museum

 

[creekhunter]

Looks about right!

 

[Tpmetal]

Yep I was thinking the same thing, I work in a glass shop and it reminds me of stuff i find in equipment and furnaces. Look up local glass history where you found it.

 

[Marccc1991]

Where can I find any information about the glass history in specific areas?

Edit: I found some info about iron smelting factories around 1500-1600 in that area. So it all starts making sense I guess...

 

[Eu_citzen]

Slag indeed.