The Holy Thorn Reliquary in The Waddesdon Collection, British Museum, London. It is only 30cm high.
Date: 1400 (circa)
Photos taken (through glass) January 2019 with a Sony a6000 and processed in Agisoft Photoscan.
https://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=42845&partId=1