That looks like you're into a good age. Sounds like easy digging too. What color is that chunk of glass? If I were you I wouldn't break it up. It looks like a chunk of glass from a marble factory, and could be old. You can get new ones at a pet shop for arrowhead making. Are you anywhere near an old glass factory?
Not sure Kent. I know it's an old dump and it's full of broken window glass a larger chunks of glass. I also find alot of marbles in there, but none that looked like that! The digging there is hit and miss. Sometimes you can dig a big hole and not find much, other times they're popping out with the first shovel or two. They came in on it with dozers and removed alot of it... it's on a construction site and going to be built on soon!!! Chris Capley