Late Edwardian Black, Starr and Frost Opal and Diamond Pendant Brooch

Dating to the first or second decade of the twentieth century, this delightful pendant brooch by Black, Starr and Frost centers on a magical 25 carat opal gumball filled with a dazzling array of colors. Flecks of neon green, lilac purple and electric blue are washed with splashes of iridescent yellow, creating a spectacular play-of-color. The elegant shield-shaped frame has been intricately hand fabricated in platinum, accented with .70 carats of glittering old cut diamonds. Accompanied by a gemological report from GIA stating: natural opal.

Measurements: 37 x 28 mm wide

Opal: estimated 25 carats, 19.70 x 19.90 x 11.51 mm

Diamonds: estimated .70 total carats of old cut diamonds

Weight: 12.2 grams

Metal: platinum

Markings: BS&F indicates the American jeweler Black, Starr & Frost

Notes: Founded in 1810 by Isaac Marquand – Black, Starr & Frost opened as Marquand & Co. at 164 Broadway in New York City, making it the oldest continuously operating jewelry firm in the United States. At that time, two store clerks – William Black and Henry Ball – eventually joined the firm, which became Black, Ball & Company. In 1912, then named Black, Starr & Frost – their offices to the southeast corner of Fifth Avenue and 48th Street.

The platinum loops were added to accommodate a thin chain so it could be worn as a necklace.