The Florentine diamond, a 137-carat pear-shaped stone that glimmers with a “fine citron” hue, adorned European royalty for centuries. View image in fullscreen A glass replica of the Florentine diamond. Another theory is that the diamond was cut by a European – the famed Flemish jeweller Lodewyk van Bercken – into a pyramidal shape. Briefly, the Shah of Persia, a 99-carat stone recut from larger diamond, was believed to part of the missing Florentine. But the stone unearthed in Canada is most certainly “the genuine, historical ‘Florentine Diamond’”, said Christoph Köchert of AE Köchert, once Austria’s imperial court jewellers.