Cartier, a sapphire and diamond pendant, early 20th century composite, the pendant of circular

Cartier, a sapphire and diamond pendant, early 20th century composite, the pendant of circular outline, bordered with calibré-cut sapphires, enclosing rows of chain spectacle-set with a pair of circular-cut diamonds, mounted in platinum, length 3.2cm, partially signed Cartier Paris Londres, French assay mark for 18ct gold, chains possibly later added, case stamped Cartier London