HIGHLY MATHEMATICAL ART DECO OSMIOR JEWEL
Designed as a wearable Osmior analog of a Schlegel half-solid runcinated tesseract joined to a hexagonal plane. The centrally set hexagonal aquamarine framed by angular slopes of blue-green plique-a-jour enamel and diamonds, textured edge with four clusters of four OEC diamond and four larger OEC diamonds in millegrained platinum collets. Aquamarine 18.5 x 16 x 10 mm, approx. 16 cts., four OEC diamonds approx. 1.0 cts. TW, melee approx. 2.45 cts. TW. Gold pin stem and trombone clasp, integral bail for pendant wear. Probably French. Ca. 1925. Unmarked. 2 1/2" x 2" x 1/2". 14.6 dwt. Note: Osmior (or Plator or Platinor) developed in 1918 as a less expensive platinum substitute, was popular with Art Deco period artisan jewelers. Assay information: Back of Brooch: Ruthenium 0.046; Rhodium 0.147; Palladium 0.769; Silver 75.36; Platinum 19.75; Gold 1.87. Front of Brooch: Ruthenium 0.068; Rhodium 0.279; Palladium 1.02; Silver 78.13; Cadmium 0.218; Platinum 18.18; Gold 1.54; Lead 0.144.
Estimate: $6,000 - $8,000