Slag was mentioned on the "What Did You Find" Pop-Pop Point Nov 12, 2013 thread. Sharing here Grandma Betty's Slag Collection. These pieces were found in Flea Markets in Central PA, Northumberland & Union Counties. However Betty can remember finding pieces of slag in the creeks in this area as a child. The last photo is Betty this morning at one of her favorite flea markets. She is a true collector as this was 7:00 AM & it was 19 degrees F out.