18k GOLD Greyhound Dog and Sapphire Sewing BUTTON DECO/Victorian

Super rare 18k solid gold button from the art deco (most likely) time period. It features a shiny gold base with what I believe is a platinum greyhound applied with a collar studded with sapphires. The yellow part has been tested and is 18k however I was afraid to scratch test the dogs face so I am only guessing that it is platinum. It may be silver although it doesn't seem likely since it was not tarnished at all. The weight is a HEAVY 5.7 grams. This would look great converted into a pendant or ring. Enjoy!!!