Did Joseph Smith use the Urim and Thummim?
Just so, what is the purpose of the Urim and Thummim?
Considering the scholars' conclusion that Urim essentially means "guilty" and Thummim essentially means "innocent", this would imply that the purpose of the Urim and Thummim was an ordeal to confirm or refute suspected guilt; if the Urim was selected it meant guilt, while selection of the Thummim would mean innocence.
Beside this, how did Joseph Smith obtain the brown seer stone?
According to an uncorroborated account by Hale, Smith attempted to locate the mine by burying his face in a hat containing the seer stone; however, as the treasure hunters got close to their objective, Smith said that an enchantment became so strong that Smith could no longer see it.
Joseph Smith's seer stone will be put on public display in an LDS Church visitors center in Harmony, Pennsylvania.