French Folk costumes are always referred to according to the old Provinces. If you look at a current map of France, the divisions you will see are Departements, which are purely administrative. The old provinces are connected with the traditions and identity of each area, They vary in size, and the exact borders have varied through history. Here is a map of France showing the current departements superimposed on the more complicated version of the old Provinces. The traditional extent of Provençe is shown in green in the southeast corner of France. I am not sure why the small area in violet on the northwest edge is separated, this is often also considered to be part of Provençe.
The people of this region traditionally spoke Provençau, a dialect of the Occitan Language of southern France. This has been mostly displaced by French according to the policy of linguistic uniformity promulgated by Paris in the early 20th cent. A minority of people in the region still speak it.
For further information on the history, language and culture of Provençe, see these articles.
I will be addressing specifically the costume of Lower Provençe, Upper Provençe refers to the higher areas further north into the mountains. Besides the more general one, the costume from the area around Nice is somewhat different, and the costume of the city of Arles and its environs is very distinct. Each of these three costumes is often portrayed as the Provençal costume.There is a famous series of prints by Gardilanne, portraying the costumes of France. This one depicts a milkmaid from St. Ferre, close to Marseille.
A wide variety of jewelry is worn on appropriate occasions, brooches, chatelaines, lockets, and especially crosses. One ornament which is very typical is a black velvet band around the neck with a very ornamental cross attached. This is part of France's rich Catholic heritage.
Earrings are seldom worn, because the Coiffe generally covers the ears. These are made of fine linen with whitework embroidery, trimmed with lace which is often goffered. The cut varies, but it is generally small and fits rather closely to the head. The back is gathered, so that there is room for the hair, which is worn braided up on the back of the head. The face is generally framed with a lace frill of some sort. Here is one example of a layout and a couple of finished coifs. Others are visible in the various photos.
Mary Gostelow, 'The Complete International Book of Embroidery', New York, 1977
Rode de Basso Prouvenço, 'Le Costume Populaire Provençal', Aix-en Provençe, 1990
Andre Sainsard, 'Costumes Folkloriques Provinces Françaises', Paris, 1972
Royere, Gardilanne, Moffat et al, 'Les Costumes Regionaux de la France', New York, 1929
Charles-Brun, 'Costumes des Provinces Françaises', Paris, 1937
P. Leroux, 'Costumes Regionaux', Paris, 1940