What is Spelter Metal

In use since Civil War times Spelter, while sometimes used merely as a synonym for zinc, is often used to identify a zinc alloy. In this sense it might be an alloy of equal parts copper and zinc, i.e. a brass, used for hard soldering and brazing, or as an alloy, containing lead, that is used instead of bronze. In this usage it was common for many 19th-century cheap, cast articles such as candlesticks and clock cases and early 20th-century Art Nouveau ornaments and Art Deco figures.

The word "pewter" is thought to be derived from the word "spelter".^[1] Zinc ingots formed by smelting might also be termed spelter.

If you piece is old and you can't tell if it's brass or spelter...scratch the bottom a bit. Spelter will be silver in color.
I also know it to be called "Pot Metal"