“What was the approximate weight of the gold plates from which the Book of Mormon was translated?” Ensign, Dec. 1986, 65
Roy W. Doxey, assistant in the office of the Quorum of the Twelve. The Prophet Joseph Smith described the gold plates as follows: “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.”1
Although no specific mention of weight is made in this description, several references to the weight can be found in accounts by Joseph’s acquaintances who personally handled the plates. Joseph’s wife, Emma, recorded that she moved the linen-wrapped plates while cleaning. Martin Harris declared, “I hefted the plates many times, and should think they weighed forty or fifty pounds.”2 William Smith, brother of the Prophet, reported that he “was permitted to lift them as they laid in a pillow case; but not to see them, as it was contrary to the commands he [Joseph Smith] had received. They weighed about sixty pounds according to the best of my judgment.”3 The eight men who testify that they examined the plates say that they each lifted them.
Variations in the estimation of the weight of the plates by those who “hefted” them are due to the experience of each in judging weight. But the accounts listed above indicate that the plates were light enough to be carried without undue difficulty. Joseph Smith, for example, carried them some distance when he was forced to flee from some men seeking the plates shortly after he received them.4
Critics of the Prophet Joseph Smith have claimed that the plates may have weighed as much as two hundred pounds. Such estimates, however, are based on computation of a solid 24-karat gold object with the dimensions described by the Prophet; this estimation does not allow for the weight reduction that would naturally result from cutting the engravings, from unevenness of the leaves wrinkled by hammering, and from air space between each leaf.5
Referring to the Prophet’s statement that the plates “had the appearance of gold,” some have speculated that the metal of the plates was probably tumbaga, the name given by the Spaniards to a versatile alloy of gold and copper which could “be cast, drawn, hammered, gilded, soldered, welded, plated, hardened, annealed, polished, engraved, embossed, and inlaid.”6
Tumbaga can be treated with a simple acid like citric acid to dissolve the copper on the surface. What is then left is a shiny layer of 23-karat gold on top of a harder, more durable copper-gold alloy sheet. This process was widely used by the pre-Columbian cultures of central America to make religious objects.7
Tumbaga plates of the dimensions Joseph Smith described would weigh between fifty-three and eighty-six pounds.8
Though we may never know the exact weight of the plates, the statements of others who handled them, as well as the scriptural references to their mobility, substantiate that weight was no barrier to conveying the plates in accordance with the purposes of God.