Note: these relics are more than likely second or third-class relics, not first-class relics:
Relics
of Mary are kept in the oratory of an estate at Marsat, in the territory of
Clermont. (Gregory of Tours, Glory of the Martyrs 8 [trans. Raymond Van
Dam; Translated Texts for Historians 4; Liverpool: Liverpool University Press,
1988, 2004], 10)
10.
The fire [controlled] by the power of the relics of St. Mary
Once
I was as usual wearing relics of this blessed Virgin along with those of the holy
apostles and of the blessed Martin that had been placed in a gold cross. As I was
travelling along the road, I noticed, not far from the road, that a poor man’s
cottage was on fire. The cottage had been covered with leaves that served as
ready kindling for the flames. With his children and wife the poor man was
running about carrying water, but the flames were not dying down. Lifting the
cross from my chest I held it up against the fire; soon, in the presence of the
holy relics the entire fire stopped so [suddenly], as if there had been no
blaze. (Glory of the Martyrs 10, ibid., p. 13)
18.
The relics of the blessed Mary
Previously
I saw a man named Johannes who had departed from Gaul as a leper. He said that
he had waited for an entire year at that spot where I said the Lord had been
baptized. Frequently he washed himself in the river; when his skin was
transformed for the better, he was cured and restored to his earlier health.
From Jerusalem he received relics of the blessed Mary. He set out for his
fatherland but decided first to visit Rome. As soon as he entered the vast
mountains of Italy, he met bandits. Immediately he was robbed of his clothing;
even the reliquary in which he carried the blessed relics was seized. For these
highwaymen thought that gold coins were in the reliquary, and after breaking
the lock they closely examined everything. When they found no money in it, they
took out the relics and threw them in a fire. After beating the man, they left.
Although half-unconscious, the man got up to collect the ashes of the relics
that had burned. He found the relics lying unburned on top of smoldering
embers. He was astonished that the linen cloth in which the relics were wrapped
was so spotless that one might think it had been not tossed on coals but soaked
in water. Happily he gathered everything up and set out on the road he was
travelling; he reached Gaul in safety, I have seen many people who bathed
either in the Jordan river or in the springs of the city of Levida and were
healed of this disease. (Glory of the Martyrs 18, ibid., p. 19)