CJ Antiques has dated this Art Deco Crystal Brooch to the 1920s.
Each corner set with a raised floral motif. The outer edge with a pierced oval leaf design with detailed beadwork. Diamond G-H colour VS1.
23mm length x 19mm width
https://www.1stdibs.com/jewelry/brooches/brooches/art-deco-diamond-crystal-quartz-brooch-platinum-950/id-j_16312152/#skuId=j_16312152S1
CJ Antiques has dated this Art Deco Crystal Brooch to the 1920s.
You can view the stock and full dealer information on the CJ Antiques Profile Page