I don't think the larger beads were worn on a necklace. They would have been worn as a pendant as the Dogon wear the large granite beads. The shallow biconical shape is worn today as a pendant in Mauretania and Mali. When I consider the huge and heavy neck rings and anklets that have been worn in Africa I can only say WOW! to the strength of African men and women. These beads would have been trivia in comparison. I have attached pictures of two NEW ancient beads. The mottled one measures 71mm in diameter and the reddish quartz bead measures 52mm in diameter. They are both disk shaped. I have had cylindrical and kinda round beads in the past but I don't keep the fakes. They turn me off. If anyone wants these for examples I will send them for the cost of the post but I don't want them to be sold, PLEASE!!