Thanks fellas! I only got a couple pounds of this stuff and most of it was pretty fractured up. When you hold it up to the light it's sort of a translucent grayish tan color with black specks. I had heard of slag glass of course, but until straightarrow handed me some I'd never seen it. I'd like to get my hands on some of the colored stuff some day. As you can imagine there's not much of an iron industry in Kansas where I'm from. So it's a bit hard to come by. Next time I deliver to a steel mill, I'll ask around about it. Josh