This brooch is from France. It is made of lead paste crystal & silver. During the 18th century the wearing of religious (Christian) symbols as jewellery was highly fashionable. The most common emblem was a cross, which was often richly encrusted with gems. But in France peasant women wore crosses in the form of a dove ‘Saint Esprit’. This means literally the cross of the Holy Ghost. Doves are widely seen as a symbol of love. In China and Japan it is an emblem of long life and fidelity. And in Ancient Greece they were sacred to Aphrodite and Zeus because they brought ambrosia.
There is a small town in SW France on the banks of the River Rhone marking the site of a historical crossing called Pont Saint-Esprit. And in Quebec Province Canada there is another Saint Esprit first settled in the 18th century.