France is famous for popular devotion to the Virgin, for a lot longer than Lourdes; Black Madonna shrines go back many hundreds of years, featuring statues of Our Lady whose black appearance may be due to the material of which the statue is made; to black paint; or maybe many years of burning votive candles. Some think that the colour alludes to I am black, but comely, daughters of Jerusalem [Song of Songs 15]
In truth, no one knows. Some indeed, are not black, but are always referred to as Vierges Noires by th faithful. Some were destroyed at the Revolution, only to be recarved. Veneration is too deep to burn away.
They are found all over France, especially around the Auvergne. Some are like Notre-Dame du Puy, enthroned behind the high altar of the cathedral of Le Puy-en-Velay, or Notre-Dame de Mende, in a north chapel of that cathedral. Others may be in town-centre churches, such as Notre-Dame des Oliviers at Murat, or isolated, like Notre-Dame-d’Ay, Queen of the Haut Vivarais, in her chapel on a rocky outcrop.
But all are objects of devotion, surrounded by burning candles and ex-votos, whether metal hearts or stone plaques.