My round rocks

There is a blogger called Pablo who owns some land called Round Rock. It sounds like a pretty cool place, what with all those round rocks that were formed by a meteorite 350 million years ago or so. It's hard not to be jealous.

So imagine my joy when hubby and I were walking recently, and I glanced down... "Hey, look! Round rocks! Round rocks!"

A pause.

"It's slag," said hubby.

He is always ruining my fun like that.



I looked it up, and he was right. There are several types of slag, all of which are by-products of iron and steel furnaces.

They use it a lot for railroad track ballast.



In contrast to the round (pelletized) slag, which seems heavy for its size, this type (expanded or foamed) is incredibly lightweight. It's porous like a lava rock.

There's also a vitrified or glassy type of slag, which we found but failed to bring back. (If it ever stops raining I'll try to go back and get one of those and put the pic here, for the sake of completeness.)



My husband calls this configuration Slaghenge.