A FRENCH ART DECO DIAMOND TIARA / NECKLACE

A FRENCH ART DECO DIAMOND TIARA / NECKLACE, of graduating geometric design, set with circular-cut and baguette-cut diamonds weighing approximatley 25.00cts, mounted in platinum, detaching from the base metal frame to form a necklace, inner curve of tiara frame 42cm, tiara height to the centre 3.4cm, necklace length 35.5cm, stamped with a maker's lozenge, French control marks for platinum

A strong geometric design and the prolific use of diamonds and platinum give the present lot its unmistakably Art Deco quality. Although all the big French houses produced recognisably Art Deco jewellery, Mauboussin epitomised this combination of features from 1929, when it introduced its 'Joaillerie blanche', or 'white jewellery'. This systematically featured the pairing of diamonds and platinum, often turning the compositional relationship between the two on its head. One of their innovations was the prominence afforded for the first time to the use of platinum, as the mounts came to the fore, becoming more than mere supports to the diamonds.

This daring approach to jewellery design was typical of Mauboussin, which set itself apart for its experimental use of materials and compositions at this date. A particularly audacious design in this vein was the 'Marteau' brooch of 1935. It took the motif of geometric diamond-set borders centred with larger individual diamonds, similar to those seen in the present lot, a step further, by entrusting the thrust of the composition to bold angular structures, often in carved rock crystal, framing the gem-set elements. Its striking trapeziodal design became arguably the quintessential Mauboussin design of the 1930s, echoed in the geometric motifs seen anchoring the design of the present lot.

Another favourite feature of Mauboussin at this time, as with other French design houses, was the challenge to design transformable jewellery. Stimulated in part by the constrictions of the Great Depression, it became particularly popular from the mid-1930s, exhibited to great acclaim at the Paris Exposition Universelle of 1937 and later the New York World's Show of 1939, which closed this decade of jewellery design on the eve of the Second World War. The tiara / necklace conversion is a particularly happy combination and one that was well-known before the emergence of the transformable jewellery of the 1930s.