Frank Yellowhorse Rare vintage Navajo sterling mosaic necklace with turquoise

Heavy gauge sterling silver bib style necklace by the late Navajo artist Frank Yellowhorse. Features various geometric stones inlayed in sterling: turquoise, lapis, onyx, malachite, spiny oyster shell, and mother of pearl (maybe). Most likely made in the late 70s or early to mid 80s.