Early 20th-Century Old-Cut Diamond Platinum-Topped 14 Karat Gold Plaque Brooch

An elegant early 20th-century diamond openwork plaque brooch, dating to circa 1915–1930 and designed as an elongated rectangular panel of finely pierced floral, foliate and geometric motifs.

The brooch has been professionally tested and is constructed with a platinum-topped front over a 14-karat yellow-gold reverse, including the pin. This mixed-metal technique was widely used in fine jewellery of the late Belle Époque and early Art Deco years. Platinum provided a cool, discreet setting for diamonds and allowed for exceptionally fine pierced and millegrain-style detailing, while the gold backing added strength and flexibility to the construction.

Stylistically, the brooch sits at the transition between two important decorative movements. Its naturalistic floral ornament and airy structure retain the refinement of the Belle Époque, while its elongated rectangular outline, disciplined symmetry and increasingly architectural arrangement anticipate the emerging Art Deco aesthetic. This gives the piece a distinctive character: romantic and ornamental, yet already moving towards the cleaner geometry of the 1920s. Today, they remain highly wearable and can be styled traditionally on evening dress or more casually on a tailored jacket, coat or simple black dress. Collectors are particularly drawn to pieces that retain their original proportions, fittings and period character, as well as those that bridge the Belle Époque and Art Deco eras.

Details

* Period: Circa 1915–1930
* Style: Transitional Belle Époque to early Art Deco
* Design: Elongated rectangular openwork plaque with symmetrical floral, foliate and geometric motifs
* Stones: Old-cut and rose-cut diamonds
* Setting: Fine pierced and millegrain-style diamond settings
* Construction: Platinum-topped front over a 14-karat yellow-gold reverse
* Pin: 14-karat yellow gold, professionally tested
* Fastening: Hinged pin with period-style safety catch
* Dimensions: Approximately 5.4cm long x 2.0cm wide
* Weight: Approximately 9.4 grams
* Condition: Excellent vintage condition; professionally polished, with diamonds checked and settings secure
* Wearability: Suitable for a lapel, neckline, dress, coat or scarf
* Collectability: Desirable for its hand-pierced construction, mixed platinum-and-gold technique, period diamond cuts and transitional design between two major decorative eras

Condition & Authenticity

Each piece has been carefully inspected and is presented in very good condition, with wear consistent with its age and use. Materials and stones are assessed using standard industry methods and professional experience. Additional images or video are available on request.

Pricing & taxes

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