PORTRAIT OF AN UNKNOWN MAN IN THE COSTUME OF THE FIFTEENTH CENTURY, BY ANTONIO DEL POLLAIOLO
He holds between the thumb and index of his left hand a ring set with a naturally pointed diamond crystal
Galleria Corsini, Florence
PORTRAIT OF A VENETIAN SENATOR, BY A. DA SOLARIO
Seal ring on thumb of left hand
National Gallery, London
In all these cases the diamond is a small natural crystal of octahedral form suggesting the “diamond, a point of a stone,” of which the astronomer Manilius wrote in the first century, and, perhaps, the diamond in Berenice’s ring mentioned in the same period by the satirist Juvenal. Another ring in the British Museum, however, is set with two facetted diamonds, as well as with two other stones (No. 778 of catalogue, Plate xx, same number). Here the diamonds have unquestionably been set at a time long posterior to the making of the ring, which is believed to belong, approximately, to the same period as the others we have listed. The diamonds were probably inserted to replace two of the original stones that had fallen out of their settings.
Sir Charles Hercules Read pronounces the instances of diamond settings in ancient rings to be exceeding rare. He states that the examples above noted are the only ones of which he knows, and considers that they belong to the third or fourth century of our era.[162]