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Vintage Art Deco Style 18K Black Onyx, Mother of Pearl and Diamond Brooch

Item Details

Style: Vintage; Art Deco Style
Material: 18K Gold
Brooch Closure Type: Locking C Clasp
Hallmarks: TURK R (foreign assay) GT (pictorial markings) 750 (London, England 1979)
Total Weight (grams): 19.90

Type: Black Onyx
Shape: Geometric Tablet
Count: 4
Dimension: 20.00 mm x 13.00 mm – approximate

Type: Mother of Pearl
Shape: Marquise Tablet
Count: 1
Dimension: 37.00 mm x 17.00 mm – approximate

Type: Diamond
Shape: Round Brilliant Cut
Count: 22
Dimension: 1.70 mm – 2.00 mm
Carat Weight: 0.55 ctw
Color Grade: H – I
Clarity Grade: SI1 – Si2

  • This item has been evaluated and verified by a GIA Graduate Gemologist.
  • All diamond and gemstone grading is done under GIA standards as the mounting permits, where gemstones are present; where mountings impede accurate measurements, (estimated) dimensions are provided. All weights and measurements are estimated and approximate. Treatments for jadeite and other gemstones are assumed unless otherwise noted.
  • Pre-owned jewelry may contain minor markings/imperfections throughout.
  • While we represent items accurately on our site to the best of our ability, the color calibration of computer monitors can vary, causing colors to appear slightly different from one monitor to another. Due to this, please note that precise color representation of metal and gemstones is not always possible.


- brooch is a convertor brooch.
- one diamond is chipped.

Item #


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