[Sr(NO3)2] White powder.
An oxidizer commonly used as a red coloring agent often with chlorine donors and metal fuels in stars, flares, fountains, sparklers and other fireworks.
Although they are not interchangeable with Strontium Nitrate, other red coloring agents are strontium sulfate, strontium carbonate, and the salt strontium chloride.
Here are some fireworks compositions that use strontium nitrate:
Strontium Nitrate Sparklers
Red Screen Sliced Stars
Red Gerb Composition