A pair of retro gold and diamond 'Tourbillon' brooches, by Sterlé. Photo Christie's Image Ltd 2014

Each designed as a stylized gold wire wing with pavé-set diamond base and brilliant-cut diamond terminal, 1954, 5.0 cm, with French assay mark for gold. With maker's mark for Sterlé (2). Estimate CHF20,000 – CHF30,000 ($22,811 - $34,216)

Literature: V. Jutheau, Sterlé Joaillier Paris, Editions Vecteurs, 1990, Paris, pp. 119-120 and 161-162 for drawings and illustrations of the brooches. 

Christie's. GENEVA MAGNIFICENT JEWELS. 14 May 2014, Geneva - http://www.christies.com/