A pair of Art Deco emerald diamond and black onyx clip brooches

A pair of Art Deco emerald diamond and black onyx clip brooches, each clip centred with a cushion shaped emerald within a surround of graduated cushion shaped diamonds and highlighted with sections of carved black onyx in platinum. 3.7cm wide. With Cartier box. Family tradition holds that the original owner commissioned Cartier to make this piece from stones provided by herself.