Necklace with opal, 4 ruby carrés and brilliant-cut diamonds totaling ca. 2 ct,

Necklace with beautiful oval opal ca. 5.9 ct, 4 carré-cut rubies ca. 0.63 ct and brilliant-cut diamonds, totalling ca. 2 ct, ca. WHITE-STW (H-J)/SI, 18K yellow gold, 38.5 g, L: 43 cm, late 20th century, minor signs of wear.