The Vintage Vitro Agate Marbles 42 Pieces Mixed Lot features a variety of colors and sizes, from Pee Wee to Player, making it a versatile collection for marble enthusiasts. These machine-made marbles from the pre-1970 era bring a nostalgic touch and are suitable for collectors aged 17 years and up. The Vitro Agate brand adds a unique element to this vintage set, making it a desirable addition to any collection of marbles. I’m not a marble expert but I think this is what they are. Some have UV qualities, most are like new never played with. I have two lotts of these for sale.