Also known as 'Thunderballs' or 'Shaman Stones', Moqui Marbles come from the Navajo Sandstone Formation in Utah, U.S.A.
They are named after the Moqui Indians who inhabitated the land where they were found. Exactly how Moqui Marbles were formed is not clear. They are ironstone concretions, comprising a compacted sandstone surrounded by a shell of hematite, believed to have been formed 130 to 155 million years ago.
In the native indian Hopi language, 'moqui' means 'dearly departed one'. According to legend, the departed relatives of the Hopi would play with these 'marbles' in the evening when the spirits were allowed to visit the earth. On their return to the heavens at sunrise, they would leave the 'marbles' behind to let relatives know they were happy and well.