People often wonder what Laban’s sword looked like. Several studies have dealt with this question.
One thing we know is that this sword had to have been very sharp, because it could, with probably just one swipe, decapitate Laban. They did have swords or knives like that, used for making sacrifices. How did one sacrifice a lamb, a goat, a bull? By slitting its throat, and they knew how to do that. For Passover, for example, men would kill the lamb that would then be blessed, prepared, and the blood properly removed.
Nephi was a metallurgist; he knew how to make plates. He marveled at the workmanship of the Liahona. He also recognized the qualities of Laban’s sword, its steel blade, gold hilt. It reminds me of a dagger from King Tut’s tomb. I imagine it was a ceremonial sword or sacrificial dagger. There are ancient depictions of soldiers slitting the throat of captives. They knew how to do this.
Book of Mormon Central, "What was the Sword of Laban Like? (1 Nephi 4:9)," KnoWhy 401 (January 23, 2018).