According to Latter Day Saint theology, seer stones were used by Joseph Smith, as well as ancient prophets, to receive revelations from God. Members of the Church of Jesus Christ of Latter-day Saints (LDS Church) believe that Smith used seer stones to translate the Book of Mormon.[1][2]
Some early-19th-century Americans used seer stones in attempts to gain revelations from God or to find buried treasure.[7] From about 1819, Smith regularly practiced scrying, a form of divination in which a "seer" looked into a seer stone to receive supernatural knowledge.[8] Smith's usual procedure was to place the stone in a white stovepipe hat, put his face over the hat to block the light, and "see" the necessary information in the stone's reflections.[9][10][11] Smith and his father achieved "something of a mysterious local reputation in the profession—mysterious because there is no record that they ever found anything despite the readiness of some local residents to pay for their efforts."
After finishing the Book of Mormon translation, Smith is said to have given his brown seer stone to Oliver Cowdery, but he occasionally used his white stone to gain revelations, including his translation of what later became known as the Book of Abraham.[44] There is no evidence that Smith used the stone to dictate any of the Doctrine and Covenants revelations after November 1830.[45] During his work on his Bible translation, Smith told Orson Pratt he had stopped using the stone because he had become acquainted with "the Spirit of Prophecy and Revelation" and no longer needed it.[46] Nevertheless, in 1855, Brigham Young told the apostles that Smith had had five seer stones, and Young made it clear that Smith "did not regard his seer stones simply as relics of his youth" but had found others while church president.[47]
According to apostle Joseph Fielding Smith, the LDS Church owns one of Smith's seer stones.[48][49] Nevertheless, since the nineteenth century, no president of the church has openly used such a stone in his role as "prophet, seer, and revelator".[citation needed]
In August 2015, the LDS Church released images of one of Smith's seer stones—a rounded, smoothed, brown and black stone—in a volume of the Joseph Smith Papers Project containing the printer's manuscript of the Book of Mormon.[1][2] The stone shown in the released images has been identified by geologists as a form of jasper, found in a banded iron formation, thus called banded jasper.
https://en.wikipedia.org/wiki/Seer_stone_(Latter_Day_Saints)
See also: Cunning folk traditions and the Latter Day Saint movement
Cunning folk traditions, sometimes referred to as folk magic, were intertwined with the early culture and practice of the Latter Day Saint movement. These traditions were widespread in unorganized religion in the parts of Europe and America where the Latter Day Saint movement began in the 1820s and 1830s.[2][3] Practices of the culture included folk healing, folk medicine, folk magic, and divination, remnants of which have been incorporated or rejected to varying degrees into the liturgy, culture, and practice of modern Latter Day Saints
From about 1819, Smith regularly practiced scrying, a form of divination in which a "seer" looked into a seer stone to receive supernatural knowledge.[16] Smith usually practiced "peeping" or seeing by putting a stone at the bottom of a white stovepipe hat, putting his face over the hat to block the light, then divining information from the stone.[17] Smith and his father achieved "something of a mysterious local reputation in the profession—mysterious because there is no record that they ever found anything despite the readiness of some local residents to pay for their efforts."[18]
In late 1825, Josiah Stowell, a well-to-do farmer from South Bainbridge, Chenango County, New York, who had been searching for a lost Spanish mine near Harmony Township, Susquehanna County, Pennsylvania with another seer, traveled to Manchester to hire Smith "on account of having heard that he possessed certain keys, by which he could discern things invisible to the natural eye."[19]
https://en.wikipedia.org/wiki/Cunning_folk_traditions_and_the_Latter_Day_Saint_movement
Q.-What do you mean by Urim and Thummim?
A.-The same as were used by the prophets of old, which were two crystal stones, placed in bows something in the form of spectacles, which were found with the plates.
See https://www.josephsmithpapers.org/topic/urim-and-thummim