Holy mackeral. Those are good!
If you dig marbles from an old dump,save the broken/partially melted ones. I've got a bunch of those. You can use that glass to make new marbles. And while searching dumpsites save all the Akro Agate broken playset girls' miniature dishes & cups. I've got a ton of that stuff,too. And save all the uranium glass/vaseline glass pieces and mid 30s McKee jadite glass you find. If you can make marbles out of scrap glass there's a whole world of collectible,antique glass out there to make them with. You've got me thinking seriously about buying a kiln and molds. You can make marbles by melting 'desert glass' which has turned purple thru the addition of manganese to the glass. But this will turn the glass from purple back to clear. No problemo. Melt the glass,make marbles and place them exposed to sunlight in a tinfoil-based reflector box for two years or buy the proper UV equipment.
