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SOURCE: rec.pyrotechnics

COMMENTS: This is a "twinkling" star. Magnesium reacts slowly with ammonium perchlorate, producing ammonia and magnesium perchlorate, especially in the presence of moisture. Thus, the twinklers cannot be stored for more than 6 months, and they must be kept in a closed bag. During the smolder phase, magnesium reacts with ammonium perchlorate in the dark. In the flash phase, magnesium reacts with barium sulfate, producing hot MgO and creating a green flame. The flash is followed by another cycle, since the flash rapidly consumes the reactants in the flash zone. 

PREPARATION (parts by weight):

Magnesium powder0.230
Ammonium perchlorate0.600
Barium sulfate0.170

  1. Binder solution: dissolve 3 parts of nitrocellulose (smokeless powder or celluloid film) into 30 parts (w/v) of boiling acetone. If you're going to prepare these stars more than once, prepare more of the solution, since nitrocellulose dissolves slowly, even in refluxing acetone. Approximately 30 parts of the solution (v/w) is used each time. Nitrocellulose is used as a binder as other binders tend to interfere with the twinkling.
  2. Mix the ingredients into the binder solution in the order they appear here. Proceed as usual. 

NOTE: acetone evaporates very rapidly; the stars usually dry within a few hours.