The Holy Thorn Reliquary
Sources vary within a c. 1390-1410 window: Google Arts & Culture (British Museum partner content) gives 'before 1397'; the Wikipedia synthesis of Tait and Cherry gives 'probably in the 1390s'; Cherry's 2010 monograph title dates it '1400-10'. This record uses c. 1400-1410 as the commonly cited range and flags the spread for the editor. - Gold (used throughout the structural framework, not just the applied decoration), email en ronde bosse (enamel in the round) over cast gold figures, rock crystal, pearls, rubies, sapphires