Can't see a stamp, possibly 15 carat but guaranteed to be at least 9 carat gold. The brooch measures 26.50mm by 26.50mm.
PLEASE INSPECT PHOTOS AND READ THE DESCRIPTION CAREFULLY. The item "Lovely Antique 9 Carat Gold Large Amethyst And Seed Pearl Brooch" is in sale since Wednesday, April 18, 2018. This item is in the category "Jewellery & Watches\Vintage & Antique Jewellery\Vintage Fine Jewellery\Unknown Period". The seller is "brittonsjewellery" and is located in Clitheroe, Lancashire.
This item can be shipped to United Kingdom, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Australia, United States, Bahrain, Canada, Brazil, Japan, New Zealand, China, Israel, Hong Kong, Norway, Indonesia, Malaysia, Mexico, Singapore, South Korea, Taiwan, Thailand, Bangladesh, Bermuda, Bolivia, Barbados, Brunei darussalam, Cayman islands, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, French guiana, Iceland, Jersey, Jordan, Cambodia, Liechtenstein, Sri lanka, Macao, Monaco, Maldives, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Saudi arabia, South africa, United arab emirates, Ukraine, Chile, Bahamas, Colombia, Costa rica, Guatemala, Honduras, Jamaica, Kuwait, Panama, Qatar, Trinidad and tobago, Uruguay, Viet nam.