Sparkling mid-century convertible pendant-brooch, America, circa 1950s, crafted in solid platinum (electronically tested) with polished Retro?Modernist styling. Fitted with a hinged pin bar for brooch wear and a concealed ring bale for chain/necklace wear. Set with 85 natural gemstones: a four-prong round cabochon Australian black opal (8 x 8 x 4mm; approx. 1.60 ct) showing vivid play-of-color, plus diamonds totaling 4.04 ctw—six round brilliants in four prongs (0.48 ctw), 70 mixed European/round brilliant diamonds in flush settings (2.84 ctw), and eight straight baguettes in channel settings (0.72 ctw), all F color, VS2 clarity. Weight 14.30 grams; measures 53 x 36mm. Unmarked; electronically tested as platinum. Very good conditions. All our diamonds and colored gemstones are naturally earth-mined. Any synthetic (lab-grown) stones will be clearly indicated in the description. Upon Request, Auction House may provide an appraisal. This will carry an additional cost. Appraisals are made by our in house GIA certified Gemologist.