The Holy Thorn Reliquary in the British Museum has a single thorn that is just visible in the center.
The Rothschild reliquary that is perhaps the most elaborate of all, was created for the highly flamboyant brother of a French king around 1400. It seems strange for it to be displayed just like any other artifact in the British Museum when in its day this was the most revered object in private hands. Countless visitors wander unknowingly past the reliquary today, while in centuries past the faithful would have approached it on their knees.
+© Photo by Lucien de Guise; British Museum