For behold, Laban hath the record of the Jews and also a agenealogy of my forefathers, and they are bengraven upon plates of brass. 1 Nephi 3:3

1 Nephi claims to speak of a time period around 600 BC.  According to the website, www.copper.org, it says this about the history of brass:

     After the Copper (Chalcolithic) Age (5000 BC) came the Bronze Age (3300-1800 BC), followed later by the Iron Age (1300-600 BC). There was no 'Brass Age' because, for many years, it was not easy to make brass. Before the 18th century, zinc metal could not be made since it melts at 420ºC and boils at about 950ºC, below the temperature needed to reduce zinc oxide with charcoal. In the absence of native zinc it was necessary to make brass by mixing ground smithsonite ore (calamine) with copper and heating the mixture in a crucible. The heat was sufficient to reduce the ore to metallic state but not melt the copper. The vapor from the zinc permeated the copper to form brass, which could then be melted to give a uniform alloy.
     Only in the last millennium has brass been appreciated as an engineering alloy. Initially, bronze was easier to make using native copper and tin and was ideal for the manufacture of utensils. Pre-dynastic Egyptians knew copper very well and in hieroglyphs copper was represented by the ankh symbol 'C' also used to denote eternal life, an early appreciation of the lifetime cost-effectiveness of copper and its alloys. While tin was readily available for the manufacture of bronze, brass was little used except where its golden color was required. The Greeks knew brass as 'oreichalcos', a brilliant and white copper.
     Several Roman writers refer to brass, calling it 'Aurichalum.' It was used for the production of sesterces coins and many Romans also liked it especially for the production of golden colored helmets. They used grades containing from 11 to 28 per cent of zinc to obtain decorative colors for all types for ornamental jewelry. For the most ornate work the metal had to be very ductile and the composition preferred was 18%, nearly that of the 80/20 gilding metal still in demand.
     As mentioned, in medieval times there was no source of pure zinc.

While brass was likely around, it was very difficult to make.

"Brass" never shows up in the Bible.  To engrave on brass extensive records of geneaologies was nearly impossible.  Instead they wrote these things on scrolls.  Look at all the information that was "engraved on brass."

And after they had given thanks unto the God of Israel, my father, Lehi, took the records which were engraven upon the aplates of brass, and he did search them from the beginning.
And he beheld that they did contain the five abooks of Moses, which gave an account of the creation of the world, and also of Adam and Eve, who were our first parents;
And also a record of the Jews from the beginning, even down to the commencement of the reign of Zedekiah, king of Judah;
And also the prophecies of the holy prophets, from the beginning, even down to the commencement of the reign of Zedekiah; and also many prophecies which have been spoken by the mouth of Jeremiah.
And it came to pass that my father, Lehi, also found upon the aplates of brass a genealogy of his fathers; wherefore he knew that he was a descendant of Joseph; yea, even that Joseph who was the son of Jacob, who was sold into Egypt, and who was preserved by the hand of the Lord, that he might preserve his father, Jacob, and all his household from perishing with famine. 1 Nephi 5:10-14

That's the first 11 books of the Bible.  Impossible.

Later, in 1 Nephi 16, Nephi awoke and found a big ball of brass with two spindles (compass).  Apparently God made this miraculous contraption.

Brass was around during the time of Nephi, however, the likelihood of Nephi being about to mine, process and etch such plates would be an incredible feat.  Not impossible, but unlikely, especially the size of the project - the entire Book of Mormon.  That 268,163 words!