These are handmade graduated disk beads of jet (learn more about Jet). In the center of the necklace, fine-diameter jet heishi beads are interspersed between the larger disk beads to make the strand "round out" perfectly and move fluidly with the body. Jet is found in many places and Chris used to prefer Pennsylvania jet for his projects. These days he claims that the finest jet available is from Siberia and that's what he's been using for the last year. Finished with two handmade Kingman turquoise beads at the catch.
Jet heishi: 1/8" to 3/8" diameter; 3/32" running length