Lovely Native American genuine turquoise round beads, rare to find this large size, stabilized I am sure, a usual practice in this type of bead to make them less breakable and so they won't change color with skin oils. Best opinion is Royston mine from several experts that have examined these. Each bead measures 3/8" across and there are 36 beads of uniform size and colors, beautifully matched. They are strung on cord with a small amount of heishi at each end. The necklace measures 19" around. No cracks, we see one bead with a small open spot we think is natural and not a chip. Very hard to find vintage turquoise beads in such a uniform round shape and large size.