Saints mentions Joseph using a seer stone in a hat to translate the plates.
Saints: The Story of The Church of Jesus Christ in the Latter-Days (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 2018), 1:50
With peace restored, Joseph and Martin translated quickly. Joseph was growing into his divine role as a seer and revelator. Looking into the interpreters or another seer stone, he was able to translate whether the plates were in front of him or wrapped in one of Emma's linen cloths on the table.