Sparklers are commonly found in the u,k.Usually they are mixed in with cats eyes and vintage swirls.I assume because they look a bit like cats most people assume they are.I can remember as a kid in the 70's playing with them,even my mates had them,but they were not new marbles even then.The ones with oxblood stripes in them were always prized and were keepers, and many other vintage marbles were prized by us as kids,because they were diffrant from what we could buy as new in the shops,noticably cats eyes.So if anyone wanted to play keepsies with anything diffrant then the common cats eyes,it was always an epic game and many kids including myself went away heart broken or very happy.Its gone and got me all nostalgic now.
The sparkler of interested has been described as type 4,which is a clear base type with fine fillaments of blue and white,and sometimes purple and white.They resemble the american sunbursts only not as pretty.I believe some of these were unearthed in an archeological excavation of a bombsite from the last war.The excavation was a part of the Time Team series of programs.Has anyone else seen this program and can confirm if these marbles are indeed type 4.
Its interesting as Britain was pretty much an island fortress during that time and cut off from mainland europe, it may suggest that they were being produced from the latter part of the 1930's onwards.