MMD Members,  Being in the pyrotechnic business for almost 40 years,
I have to call attention to a note about "cutting open fireworks with
a razor blade."

The silvery powder could be many compounds, but the worst of which
would be common flash powder.  No sodium nitrate, but if any sort of
spark, or heat from the cutting would set it off and one could loose
fingers, hands, eyes, and receive severe burns.

Please do not cut open any pyrotechnic devices, ever...

Bill Klinger
Los Angeles, California, USA