Richard M. Robinson records that he was shown seer stone by Lorenzo Snow.
Richard M. Robinson, "The History of a Nephite Coin," A Personal Experience of Elder Richard M. Robinson of Grantsville, Utah, December 30, 1934, 3-5. MS 5147, CHL.
[Lorenzo Snow] went and got the money purse or leather bag that President Young had brought to the Rocky Mountains with him, also the Seer Stone and said, 'This is the Seer Stone that the Prophet Joseph used. There are very few worthy to view this, but you are.' He handed the Seer Stone to me and I couldn't express the joy that came to me as I took that stone in my hands. Words are not equal to the task of expressing such a sublime joy! He then told me to hand the Seer Stone to my wife and I handed it to her. He then blessed us with the greatest blessing I have ever heard fall from the mouth of man!
Description of the Seer Stone
The Seer Stone was the shape of an egg though not quite so large, of a gray cast something like granite but with white stripes running around it. It was transparent but had no holes, neither in the end or in the sides. I looked into the stone, but could see nothing, as I had not the gift and power of God that must accompany such a manifestation.