Zinc
From PyroGuide
Formula: Zn
Description: Metallic zinc is used in rocket propellants, for spark effects and in white smoke compositions. Zinc powder is quite heavy and zinc-based stars often require heavier lift or burst charges to propel them.
Hazards: Zinc powder in presence of nitrates can spontaneously heat up when wet.
Sources: Zinc powder is used in paints for the protection of steel. Spray cans containing an suspension of zinc powder are commonly sold in hardware stores. The zinc powder may be extracted by emptying the spray can in a large container, allowing the powder to settle, decanting the solvent and paints and repeated washing with paint thinner or acetone. However this is an expensive way to obtain zinc powder when high purity is available commercially at about $3 per pound in 50 pound drums. Unfortunately it cakes to rock hard masses in a few years on storage and requires ball milling every year to keep it usable.
Where to buy: Online.