English: Heavy gold signet ring, finely engraved with a coat of arms, oriented vertically, within a dotted border.

Images of the signet ring were examined by Dr Clive Cheesman, College of Arms, who has provided the following information:

'The ring shows the coat of arms of a family called Prestwich. The coat of arms consists of a shield and, displayed on top of a helmet, a crest. The shield is quartered, the first and fourth quarters showing a design consisting of a mermaid, reputedly granted in the mid-16th century to a family called Prestwich of Hulme, Manchester. We do not unfortunately have a precise date for this grant, which is not on official record. The second and third quarters show a more complex design consisting of a chevron with lions' faces on it and a lion between two fleurs-de-lys in the upper segment. This design was the original coat of arms of the family, predating the mermaid design, and there is other evidence to show that the family subsequently 'quartered' the old and the new designs together in this fashion. The crest is a porcupine.

In 1644 Thomas Prestwich, the head of the family was made a baronet, a title which died out with his son in 1676; but the nature of the helmet on this seal and the lack of a baronet's badge indicate that this seal was not made for a baronet. It may therefore have been made for the head of the family before 1644, or for a younger son. It is not clear to me that the first baronet had any younger sons, however; in terms both of its impressive size and of the style of its heraldic engraving I feel this object is consistent with being made for the head of the family before 1644. This may be Thomas Prestwich or his father Edmund Prestwich of Hulme (died 1629, buried in Manchester Collegiate Church - now the cathedral) - or an earlier generation.

There is evidence of the mermaid design in use from 1567 at the latest, though this seal still seems to be an early instance (possibly the earliest) of its use as a quartering together with the other design.'