Французский реликварий с частицами от Древа Истинного Животворящего Креста

19th-century French large cruciform  reliquary monstrance made of  wood decorated with solid silver caps and center detail and housing a theca with particles from the wood from the True Cross of Jesus Christ. The substantial relics are displayed in a  crystal-fronted silver theca placed in the center of the reliquary. On its back, the theca is secured by an undisturbed seal of red Spanish wax with an imprint of a coat of arms of an unidentified Roman Catholic Cardinal. The base of the monstrance has a hallmarked solid-silver plaque with the following inscription in French:

"The oak from which this cross is made is contemporary with the birth of Christianity, it was found near Sombernon, a few years ago in a Roman aqueduct whose construction dates back to the conquest of Gaul, it owes its black color to its long stay underground. [dated] 1851."