These large round brooches, known as Heftel (or Hefftlenn in old Transylvanian Saxon dialect), were worn as clasps or as pendants on special occasions by women in Transylvanian Saxony as a display of their wealth and their ethnic identity.
Originally a simple clasp used to fasten the bodice, by the 17th century it had developed into a huge pendant worn on a velvet band round the neck, generally set with genuine gems and as a display of their wealth and their ethnic identity.

The Museum Magyar Menzeti in Budapest hold three similar clasp, two illustrated in 'Schätze des Ungarischen Barock', Hanau 1991, no. 151 and 152. no. 151 is described as a breast rosette or Hemdspange with maker's mark of Johann Gebell or Johann Gorgias, Brassó (Kronstadt) circa 1630 and also illustrated in Baroque Splendour. The Art of the Hungarian Goldsmith, The Bard Graduate Center, New York, 1994, cat. no. 120. The British Museum in London also holds an example apparently unmarked (AF. 2884).
A similar brooch was sold from the The Estate of Eugene V. Thaw; Christie's, New York, 30 October, 2018, lot 379, also with the mark of Andreas Gorgias, Brasso, circa 1675.

For the maker's mark see E. Kőszeghy, Magyarországi őtvősjegywk a kőzépkortòl 1867-ig [Goldsmiths’ hallmarks in Hungary from the Middle Ages to 1867], Budapest, 1936, p. 42, no. 239.