This badge shows the head of St John the Baptist on a plate being supported by a figure flanked by two others holding candles. Badges of this type were sold to pilgrims visiting Amiens Cathedral, where a relic fragment of the skull of St John the Baptist was housed. Pilgrims’ badges were a symbol of the relationship between the saint and the pilgrim who had undertaken the journey to the relic and were conventionally worn on the individual’s hat or bag.
[A badge very like this one was found in Perth, Scotland](http://www.bbc.co.uk/ahistoryoftheworld/objects/nMwqDkEfSV6DUUEldDLCXA). John the Baptist was the town's patron saint.
D: 42mm http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=49821&partId=1&searchText=1855,0625.9&page=1