Here is a shot of the floor around my casting furnace, after about 3000 pressings. A good source for "junk in glass".

There is a stringer for each pour, so they build up like that Christmas Angel Hair tinsel decoration. There are chips of furnace bricks, bits of metal and screws from tweaking molds, small pebbles and floor sweepings in the pile. Also there is a pile of broken hearth bricks and a 2008 National EC&M commemorative for size reference. Can you find it? There are also about 6 different colors of glass.

If this was Brookfield, I'm sure all this stuff would get thrown back into the furnaces. Back in the day when barrels and wooden crates were used for containers, there would have been a lot of nails in the mix, to provide some good amber streaking.