There’s a lot of evidence in the archaeological record for using recycled glass to make new beads. You can largely tell based on any sort of streaking or marbling in the color of the glass that doesn’t look intentional. So if there’s a blue bead, but the blue isn’t uniform (e.g. it has small, darker blue streaks in it like the photo to the right), then it’s most likely recycled.
In archaeology, we tend to think recycled glass beads were made by melting down chunks of broken glass and then turning those into beads. That’s where the streaks come from. But this past week, I was looking on Etsy for some seed beads and came across recycled glass beads made in much the same way stone beads are – through grinding and drilling.
And what was most interesting to me was that the shape of these beads I saw on Etsy were identical to beads I’d seen from early medieval archaeological contexts in Scotland. When I saw them in Scotland, I hadn’t really seen beads of that type or color before, and a colleague and I both determined that the beads must be from a later period.
Now, I’m not saying those beads were made in exactly the same way as the ones I found on Etsy. But it’s something to think about. There’s no reason why you couldn’t make glass beads from recycled glass in that way. So while there are beads where recycling is clear due to the streaks in the glass, there are probably many beads that were ground down and then drilled out of recycled materials. I’m not entirely sure how we would identify them, but it’s an interesting thought and certainly something to keep in mind when looking at beads archaeologically.