What a beautiful vintage brooch!! This fine piece measures 23.5 mm across by 23.5 mm long ( 0.9 of an inch ) and weighs 4.4 grams.
It was assembled from 21 separate parts which were soldered together or connected with tube rivets ( all diamond setting riveted to the main form). Even though the design is geometric the textured surface and green enamel suggests the inspiration came from nature. A plant or may be a sea creature. The brooch is center set with an old European cut diamond measuring 5.2 mm in diameter and 3.39 mm in depth. It appears to be G in color and VS1 in clarity. European cut diamonds are thicker than modern, brilliant cut diamonds. Therefore we are estimating the weight of this diamond at about 0.63 carats. The center diamond is surrounded by eight smaller European cut diamonds which are about 2 points each.
These are about H,I color and VS to SI clarity. As you see in the enlarged pictures, some of the green enamel dots have fallen off over time. This however does not detract from the beauty of this brooch. The piece is stamped 14K on the pin and we had also tested it with a 14K gold testing acid.