Boucheron, a fine and rare natural pearl and diamond necklace, first half 20th century, composed of

Boucheron, a fine and rare natural pearl and diamond necklace, first half 20th century, composed of two strands of graduated natural pearls measuring approximately 2.6-8.0mm, to a clasp set with an antique marquise-shaped diamond, length 48cm, signed Boucheron Paris, French assay marks for platinum and 18ct gold

Accompanied by report no. 22183, dated 30th September 2022, from the Gem & Pearl Laboratory, stating that the 188 pearls are natural, saltwater