Necklace with heart clasp, 4 diamonds

Necklace with heart shaped clasp, 4 diamonds (different cuts), totalling ca. 0.52 ct, good colour and clarity, navette cut sapphire, ca. 5.3 x 2.4 mm, round emerald, D: ca. 3.1 mm, round ruby, D: ca. 3.4 mm, 18K yellow gold, 68,3 g, chain in braid pattern, D (chain): 6,5 mm, L: 45 cm, heart with bajonette clasps on both sides, late 20th century, minimal signs of wear.