An antique turquoise and diamond plaque brooch, yellow gold and silver, Georgian, presented as a scrolled drop panel brooch of pierced grain set panels of mine cut diamonds, detailed by feature larger stones each in finely grain set bezels, centred by a turquoise set floral cluster within diamond frame, dropping to a single articulated fleur-de-lys panel set with teardrop turquoise and further diamonds, fitted with pin to reverse