Doctrines of Salvation, 3:225 “SEER STONE NOT USED IN BOOK OF MORMON TRANSLATION.
We have been taught since the days of the Prophet that the Urim and Thummim were returned with the plates to the angel. We have no record of the Prophet having the Urim and Thummim after the organization of the Church…” – Joseph Fielding Smith
LDS Gospel Topic Essay, ‘Book of Mormon Translation’ “The other instrument, which Joseph Smith discovered in the ground years before he retrieved the gold plates, was a small oval stone, or “seer stone.” As a young man during the 1820s, Joseph Smith, like others in his day, used a seer stone to look for lost objects and buried treasure. As Joseph grew to understand his prophetic calling, he learned that he could use this stone for the higher purpose of translating scripture.
Apparently for convenience, Joseph often translated with the single seer stone rather than the two stones bound together to form the interpreters. These two instruments—the interpreters and the seer stone—were apparently interchangeable and worked in much the same way such that, in the course of time, Joseph Smith and his associates often used the term “Urim and Thummim” to refer to the single stone as well as the interpreters…” (more…)