1 Ne 3:3 plates of brass

Some have argued that the description of brass in the Book of Mormon is an anachronism.  However, the same term is used in the Bible as early as Genesis 4:22. Both descriptions probably describe a copper alloy which is different than the current definition. Brass is an alloy of copper and nickel. Bronze is an alloy of copper and tin. The latter was much more common in Old Testament times, but by the 17^th and 18^th centuries, the word “bronze” was not yet in common usage. 

Hugh Nibley

“When we see brass in the Old Testament, are we supposed to read bronze? Answer: Well, you can read bronze. They did have brass, the alloy of copper and nickel, but, of course, copper and tin was much commoner. The word bronze doesn't occur in the King James Bible at all because it wasn't used until the 1880s. It wasn't an English word at all; it was a French word. We use brass which means bronze…. In Joseph Smith's time they didn't use the word bronze at all. That was a word for artists in Paris to use, and it was a new thing.” (Teachings of the Book of Mormon, lecture 10, p. 141)