Before the Temple of Ceres at Patras, there was a fountain, separated from the temple by a wall, and there was an oracle, very truthful, not for all events, but for the sick only. The sick person let down a mirror, suspended by a thread till its based touched the surface of the water, having first prayed to the goddess and offered incense. Then looking in the mirror, he saw the presage of death or recovery, according as the face appeared fresh and healthy, or of a ghastly aspect.
In medieval times, transparent stones were used, such as beryl, which among the Scots were called "stones of power." These were essentially early crystal balls.
The Urim and Thummim described in the Old Testament are not described in detail, and some have suggested that they were between two and twelve crystals used for divination. Here's Dale Morgan on peepstone history and use:
The remarkable occupation which Joseph called "glass-looking" 13 has a history old if not always honored. To recover the lost, divine the unknown, and reveal the future, the ancient Greeks employed magic mirrors, sacred springs, and even pure water in a goblet. Round pieces of rock crystal and other stones of strange shape or color were used by scryers in Europe at least from the second century, and three hundred years before Joseph's time, a "cristal stone wheryn a chylde shall loke, and see many thyngs" was an object of curious note in England. 14 Divining rods, which usually were forked twigs cut from witch hazel, willow, peach, or some other favored tree, have a similar antiquity, dating back to the times of the Medes and the Persians, but the employment of rhabdomancy [p.236] specifically for locating mines and buried treasure seems to have developed about the fifteenth century in the Harz Mountains of Germany. The practice was brought to Cornwall by German miners in Elizabethan times, and became general in England and western Europe during the next century. 15 The evolution of practice and belief in America has not been the subject of a scholarly investigation, 16 but the matured folklore as it found expression at the backwoods level was graphically described in the Palmyra Reflector early in 1831:
Mineral rods and balls, (as they were called by the imposter who made use of them,) were supposed to be infallible guides to these sources of wealth—"peep stones" or pebbles, taken promiscuously from the brook or field, were placed in a hat or other situation excluded from the light, when some wizard or witch (for these performances were not confined to either sex) applied their eyes, and nearly starting their balls from their sockets, declared they saw all the wonders of nature, including of course, ample stores of silver and gold.
It is more than probable [said the Reflector in the skeptical tradition to which it was dedicated] that some of these deluded people, by having their imaginations heated to the highest pitch of excitment, and by straining their eyes until they were suffused with tears, might have, through the medium of some trifling emmision of the ray of light, receive[d] imperfect images on the retina, when their fancies could create the rest. Be this however as it may, people busied themselves in consulting these blind oracles, while the ground nightly opened in various places by men who were too lazy or idle to labor for bread in the day time, displayed a zeal and perserverance in this business worthy of a better cause.
In early church history, they were used frequently, and not only by the president of the church. Here's a description from Priddy Meeks about the use of seer stones in early Utah:
A seer's stone appears to me to be the connecting link between the visible and invisible worlds. I am not prepared to say to what extent discoveries may be made in the invisible world through these means, but I am prepared to say that truthful discoveries, (I am fully convinced), have been made by those means on certain conditions. It is not safe to depend on peepstone in any case where evil spirits have the power to put false appearances before them while looking in a peepstone. If evil influences will not interfere, the verdict will be as true as preaching. That is my experience in the matter; also the Patriarch, Hiram Smith, the brother of the Prophet Joseph Smith, held the same idea, but stated that our faith was not strong enough to overcome the evil influences that might interfere, but seemed to think that time would come. I have seen peepstones as well polished as a fiddle with a nice hole through one end that belonged to the ancients. I asked Brother Smith the use for that hole; he said the same as a watch chain to keep from losing it. He said in time of war the Nephites had the advantage of their enemies by looking in the seerstone which would reveal whatever they wished to know. (I believe a peepstone is of the same piece with the Urim and Thummim, if we understood it.)
I find it interesting that no other Christian religion believes in the use of seer stones. As far as I can tell, the use of seer stones to find things has a specific connection to frontier America at the time of Joseph Smith.
Dale Morgan describes one peepstone/seer stone user:
A vagabond fortune-teller who lived at Sodus and had once been committed to the county jail for "juggling," Walters was said to have been paid three dollars a day for the services he rendered to the early seekers after buried treasure. With his rusty sword, his peepstone, his stuffed toad, and other paraphernalia no less impressive, Walters carried a copy of Cicero's Orations in Latin, from which, said the Reflector, "he read long and loud to his credulous hearers, uttering at the same time an unintelligible jargon, which he would afterwards pretend to interpret, and explain, as a record of the former inhabitants of America, and a particular account of the numerous situations where they had deposited their treasures previous to their final extirpation.... Walters assembled his nightly band of money-diggers in the town of Manchester, at a point designated in his magical book, and drawing a circle around the laborers, with the point of an old rusty sword, and using sundry other incantations, for the purpose of propitiating the spirit, absolutely sacrificed a fowl, ('Rooster')in the presence of his awe-stricken companions, to the foul spirit, whom ignorance had created the guardian of hidden wealth; and after digging until day-light, his deluded employers retired to their several habitations, fatigued and disappointed."
Porter Rockwell's sister recounts:
"There was considerable digging for money in our neighborhood by men, women, and children. I never knew of their finding any. I saw a large hole dug on Nathaniel Smith's farm, which was sandy. I saw Joshua Stafford's peep-stone which looked like white marble and had a hole through the center. Sallie Chase, a Methodist, had one and people would go to her to find lost and hidden things." Sally Chase's stone was described by her brother Abel in March 1881 as "dark looking...a peculiar stone" (Saints' Herald, June 1, 1881), while Lucy Mack Smith has referred to it as "a green glass" (Biographical Sketches [Liverpool, 1853], p. 109).
Again from Dale Morgan:
How Joseph found his peepstone, or as Mormon annals call it indignified reproof, his "seerstone," was related by his father in 1830 to two curious callers. Some years before, he said, his son had happened upon a man who looked into a dark stone and told people where to dig for money and other things. "Joseph requested the privilege of looking into the stone, which he did by putting his face into the hat where the stone was. It proved to be not the right stone for him, but he could see some things, and among them, he saw the [p.234] stone, and where it was, in which he wished to see." The place where he saw the stone was not far from their house; and, under pretense of digging a well, they found water and the stone at a depth of twenty or twenty-two feet. After this, Joseph spent about two years looking into this stone, telling fortunes, where to find lost things, and where to dig for money and other hidden treasures.
It seems to me that Mormon seer stones are more likely a relic of upstate New York culture and folk religion than they are a restoration of an ancient religious practice.
What say ye?