Strontium oxalate

Strontium oxalate is a compound with the chemical formula SrC₂O₄. Strontium oxalate can exist either in a hydrated form (SrC₂O₄·nH₂O) or as the acidic salt of strontium oxalate (SrC₂O₄·mH₂C₂O₄·nH₂O).^{[verification needed]}

With the addition of heat, strontium oxalate will decompose based on the following reaction:

Strontium oxalate is a useful red color emitter for use in pyrotechnics. It decomposes into strontium oxide, a good scarlet red emitter with two strong peaks at 595 and 597 nm. The oxide reacts with moisture in the atmosphere to form the hydroxide, so its three strong peaks of 682 nm, 671 nm, and 606 nm are also relevant.

Decomposition produces carbon monoxide (CO), which can reduce magnesium oxide (a broad spectrum emitter which can wash out colors) to magnesium gas, resulting in a more transparent flame. This makes it a better emitter than other common strontium compounds in the presence of magnesium:

MgO(s) + CO → Mg(g) + CO₂

When magnesium is not present, there is no benefit from the production of CO gas and strontium carbonate is usually preferable.

Chlorine donors or chlorinated oxidizers result in a shift towards formation of strontium chloride which produces a slightly different, deeper red spectrum, having its three strongest peaks at 674 nm, 661 nm, and 636 nm.