I discovered these at Tucson and paid a bit much because i'd never seen them before- however they then turned up on various sales tables on strands as himalayan prayer beads.
they appear to be recognisable as round fat shell beads with a spiral structure, but they have been decorated with lettering - i'm told on each bead it says "Om Mani Padme Hum" and looks as though the background area has been stained with a dark brown colour- maybe tea?
anyway they belong in the lettering category as well as the "Beads Made From Thick Shell" category.
i have been able to give a single bead to each family member who might need encouragement, blessings or extra luck at this moment...