If Paul Lévi and Jean-Paul Poirot are to be believed, rue Lafayette, which has been home to the majority of Parisian gem dealers since the 19th century, is thought to have been home to almost 300 fine pearl merchants between the two world wars, between numbers 1 and 100. The sheer size of this number is striking when compared with the current state of the fine pearl market, both within the capital and worldwide. As well as unraveling the final mysteries surrounding this biomineral, the main aim is to show the extent to which pearls inspired Parisian jewelers and artists of all kinds, both young and old. They all seem to have been driven by the same pearlomania, whatever their medium, from opera to cinema, painting, photography, posters or illustrated books, to the point of making the pearl one of the symbolic forms of the Roaring Twenties. Text in English and French