Seer stones were common among those involved with folk magic in the 1820's and 1830's in New York/New England. More than one of Smith's seer stones is in the First Presidency vault according to multiple sources who have seen them, as well as the Urim and Thumim. Among those sources are former BYU history professor Dr. D. Michael Quinn, who was excommunicated after publishing Early Mormonism and the Magic World View, dealing with seer stones, Smith's Jupiter Talisman, and other links between popular folk magic of Smith's upbringing and his early family life.
This seer stone of Smith is in the LDS Wilford Woodruff Museum. It belonged to Smith's widow, Emma Hale Smith.
--MormonDude(Can you NOT see that Joseph {pbuh} invented the Ritz® cracker???)