Woodbridge Antiques has dated this piece to the Edwardian era.
There is a good fastening pin on the back and it is stamped 9ct.

Beautiful gift for a lover of opals! Birth stone for the month of October!
Condition: The opal is in super condition, as is the brooch. (The fastening pin is slightly bent, commensurate with age and does not affect the item in any way, mentioned only for complete accuracy.)
Measurements: Width of brooch: 6.6 cm Weight: 2.9 grams
Weights and measurements are approximate.
38073
Woodbridge Antiques has dated this piece to the Edwardian era.
Specialists in quality antique silver, fine jewellery & accessories
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