Vintage 1980s 30-Inch 10mm Malachite & Onyx Bead Necklace 14K Gold. The 56 round malachite beads are brightly colored with beautiful striations and measure from 10.3 to 10.5 mm each. The necklace is strung on knotted silk cording. There six elongated twist onyx beads accented on either side by 14K gold cylindrical beads. The locking insert clasp is fashioned from a black onyx bead and the overall length is an ideal 30 inches. The insert of the clasp is marked 585 for 14 karat gold. Condition is excellent.