The head is higher carat, at least 18ct but I suspect 22ct, but the construction of the pin makes testing awkward. Dates to the Later Georgian to early Victorian era. The opal has survived well aside from age crazing, very fine lines which aren't detectable to the naked eye unless under very close scrutiny. The enamel also appears pretty much intact and is a gorgeous vivid royal blue. Rose cut diamonds all present to ends of claws, and so rare to see set like this.A stunning little brooch, a classic beauty. Opal measures 12mm by 8mm. Stick pin measures 63.3mm in total length. The item "Georgian Opal Rose Cut Diamond Blue Enamel Gold Stick Pin Brooch" is in sale since Friday, February 14, 2020. This item is in the category "Jewellery & Watches\Vintage & Antique Jewellery\Vintage Fine Jewellery\Pre-1837". The seller is "vintagegems2011" and is located in Lincolnshire. This item can be shipped worldwide.