The book was written by many ancient prophets by the spirit of prophecy and revelation. Their words, written on gold plates, were quoted and abridged by a prophet-historian named Mormon.
These records were engraven on plates which had the appearance of gold, each plate was six inches wide and eight inches long, and not quite so thick as common tin. They were filled with engravings, in Egyptian characters, and bound together in a volume as the leaves of a book, with three rings running through the whole. The volume was something near six inches in thickness, a part of which was sealed. The characters on the unsealed part were small, and beautifully engraved. The whole book exhibited many marks of antiquity in its construction, and much skill in the art of engraving. History of the Church, 4:537