24 Vintage Glass Knuckle Bone Buttons 1.2cm Buttons.

Smooth white glass, moulded into an unusual shape - looks like knuckle bones to me.
I expect it was done this way to add depth and interest as they catch the light on the surfaces. Their display card suggests 1930s/40s.
They are 1.2cm wide and have an integral glass shank on the back.
I just have 1 sheet of 24.