2020 Come Follow Me Manual References Joseph using a seer stone to translate plates.
Book of Mormon 2020: Come, Follow Me—For Individuals and Families (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 2019), 3
How was the Book of Mormon translated?
The Book of Mormon was translated "by the gift and power of God." We don't know many details about the miraculous translation process, but we do know that Joseph Smith was a seer, aided by instruments that God had prepared: two transparent stones called the Urim and Thummim and another stone called a seer stone. Joseph saw in these stones the English interpretation of the characters on the plates, and he read the translation aloud while a scribe recorded it. Each of Joseph's scribes testified that God's power was manifest in the translation of this sacred work.