The story goes like this. NASA was testing different materials for the Space Shuttle's reentry thermal protection. (Yes, I bought it a long time ago.) This ball was some of the material tried but rejected. The excess material was offered for sale to whomever might want lead glass in bulk. Cool story but I can't prove it. I can say this isn't the same lead glass you would find in crystal glassware, bowls, or figurines. Crystal contains 24 to 40% lead by weight. It hits it's maximum sparkle around 33%. This little ball contains 80% lead. I always get the remark, "Boy, this is heavy." when someone picks it up.